Eliminate GPUI View, ViewContext, and WindowContext types (#22632)

There's still a bit more work to do on this, but this PR is compiling
(with warnings) after eliminating the key types. When the tasks below
are complete, this will be the new narrative for GPUI:

- `Entity<T>` - This replaces `View<T>`/`Model<T>`. It represents a unit
of state, and if `T` implements `Render`, then `Entity<T>` implements
`Element`.
- `&mut App` This replaces `AppContext` and represents the app.
- `&mut Context<T>` This replaces `ModelContext` and derefs to `App`. It
is provided by the framework when updating an entity.
- `&mut Window` Broken out of `&mut WindowContext` which no longer
exists. Every method that once took `&mut WindowContext` now takes `&mut
Window, &mut App` and every method that took `&mut ViewContext<T>` now
takes `&mut Window, &mut Context<T>`

Not pictured here are the two other failed attempts. It's been quite a
month!

Tasks:

- [x] Remove `View`, `ViewContext`, `WindowContext` and thread through
`Window`
- [x] [@cole-miller @mikayla-maki] Redraw window when entities change
- [x] [@cole-miller @mikayla-maki] Get examples and Zed running
- [x] [@cole-miller @mikayla-maki] Fix Zed rendering
- [x] [@mikayla-maki] Fix todo! macros and comments
- [x] Fix a bug where the editor would not be redrawn because of view
caching
- [x] remove publicness window.notify() and replace with
`AppContext::notify`
- [x] remove `observe_new_window_models`, replace with
`observe_new_models` with an optional window
- [x] Fix a bug where the project panel would not be redrawn because of
the wrong refresh() call being used
- [x] Fix the tests
- [x] Fix warnings by eliminating `Window` params or using `_`
- [x] Fix conflicts
- [x] Simplify generic code where possible
- [x] Rename types
- [ ] Update docs

### issues post merge

- [x] Issues switching between normal and insert mode
- [x] Assistant re-rendering failure
- [x] Vim test failures
- [x] Mac build issue



Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>
Co-authored-by: Cole Miller <cole@zed.dev>
Co-authored-by: Mikayla <mikayla@zed.dev>
Co-authored-by: Joseph <joseph@zed.dev>
Co-authored-by: max <max@zed.dev>
Co-authored-by: Michael Sloan <michael@zed.dev>
Co-authored-by: Mikayla Maki <mikaylamaki@Mikaylas-MacBook-Pro.local>
Co-authored-by: Mikayla <mikayla.c.maki@gmail.com>
Co-authored-by: joão <joao@zed.dev>

crates/ui/src/styles/typography.rs

@@ -1,6 +1,5 @@
 use gpui::{
-    div, rems, AppContext, IntoElement, ParentElement, Rems, RenderOnce, SharedString, Styled,
-    WindowContext,
+    div, rems, App, IntoElement, ParentElement, Rems, RenderOnce, SharedString, Styled, Window,
 };
 use settings::Settings;
 use theme::{ActiveTheme, ThemeSettings};
@@ -10,7 +9,7 @@ use crate::{rems_from_px, Color};
 /// Extends [`gpui::Styled`] with typography-related styling methods.
 pub trait StyledTypography: Styled + Sized {
     /// Sets the font family to the buffer font.
-    fn font_buffer(self, cx: &WindowContext) -> Self {
+    fn font_buffer(self, cx: &App) -> Self {
         let settings = ThemeSettings::get_global(cx);
         let buffer_font_family = settings.buffer_font.family.clone();
 
@@ -18,7 +17,7 @@ pub trait StyledTypography: Styled + Sized {
     }
 
     /// Sets the font family to the UI font.
-    fn font_ui(self, cx: &WindowContext) -> Self {
+    fn font_ui(self, cx: &App) -> Self {
         let settings = ThemeSettings::get_global(cx);
         let ui_font_family = settings.ui_font.family.clone();
 
@@ -26,7 +25,7 @@ pub trait StyledTypography: Styled + Sized {
     }
 
     /// Sets the text size using a [`UiTextSize`].
-    fn text_ui_size(self, size: TextSize, cx: &WindowContext) -> Self {
+    fn text_ui_size(self, size: TextSize, cx: &App) -> Self {
         self.text_size(size.rems(cx))
     }
 
@@ -37,7 +36,7 @@ pub trait StyledTypography: Styled + Sized {
     /// Note: The absolute size of this text will change based on a user's `ui_scale` setting.
     ///
     /// Use `text_ui` for regular-sized text.
-    fn text_ui_lg(self, cx: &WindowContext) -> Self {
+    fn text_ui_lg(self, cx: &App) -> Self {
         self.text_size(TextSize::Large.rems(cx))
     }
 
@@ -48,7 +47,7 @@ pub trait StyledTypography: Styled + Sized {
     /// Note: The absolute size of this text will change based on a user's `ui_scale` setting.
     ///
     /// Use `text_ui_sm` for smaller text.
-    fn text_ui(self, cx: &WindowContext) -> Self {
+    fn text_ui(self, cx: &App) -> Self {
         self.text_size(TextSize::default().rems(cx))
     }
 
@@ -59,7 +58,7 @@ pub trait StyledTypography: Styled + Sized {
     /// Note: The absolute size of this text will change based on a user's `ui_scale` setting.
     ///
     /// Use `text_ui` for regular-sized text.
-    fn text_ui_sm(self, cx: &WindowContext) -> Self {
+    fn text_ui_sm(self, cx: &App) -> Self {
         self.text_size(TextSize::Small.rems(cx))
     }
 
@@ -70,7 +69,7 @@ pub trait StyledTypography: Styled + Sized {
     /// Note: The absolute size of this text will change based on a user's `ui_scale` setting.
     ///
     /// Use `text_ui` for regular-sized text.
-    fn text_ui_xs(self, cx: &WindowContext) -> Self {
+    fn text_ui_xs(self, cx: &App) -> Self {
         self.text_size(TextSize::XSmall.rems(cx))
     }
 
@@ -80,7 +79,7 @@ pub trait StyledTypography: Styled + Sized {
     ///
     /// This should only be used for text that is displayed in a buffer,
     /// or other places that text needs to match the user's buffer font size.
-    fn text_buffer(self, cx: &WindowContext) -> Self {
+    fn text_buffer(self, cx: &App) -> Self {
         let settings = ThemeSettings::get_global(cx);
         self.text_size(settings.buffer_font_size())
     }
@@ -131,7 +130,7 @@ pub enum TextSize {
 
 impl TextSize {
     /// Returns the text size in rems.
-    pub fn rems(self, cx: &AppContext) -> Rems {
+    pub fn rems(self, cx: &App) -> Rems {
         let theme_settings = ThemeSettings::get_global(cx);
 
         match self {
@@ -197,7 +196,7 @@ pub struct Headline {
 }
 
 impl RenderOnce for Headline {
-    fn render(self, cx: &mut WindowContext) -> impl IntoElement {
+    fn render(self, _window: &mut Window, cx: &mut App) -> impl IntoElement {
         let ui_font = ThemeSettings::get_global(cx).ui_font.clone();
 
         div()