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/language_model/src/language_model.rs

@@ -10,7 +10,7 @@ pub mod fake_provider;
 use anyhow::Result;
 use futures::FutureExt;
 use futures::{future::BoxFuture, stream::BoxStream, StreamExt, TryStreamExt as _};
-use gpui::{AnyElement, AnyView, AppContext, AsyncAppContext, SharedString, Task, WindowContext};
+use gpui::{AnyElement, AnyView, App, AsyncAppContext, SharedString, Task, Window};
 pub use model::*;
 use proto::Plan;
 pub use rate_limiter::*;
@@ -25,7 +25,7 @@ use ui::IconName;
 
 pub const ZED_CLOUD_PROVIDER_ID: &str = "zed.dev";
 
-pub fn init(cx: &mut AppContext) {
+pub fn init(cx: &mut App) {
     registry::init(cx);
 }
 
@@ -113,7 +113,7 @@ pub trait LanguageModel: Send + Sync {
     fn provider_name(&self) -> LanguageModelProviderName;
     fn telemetry_id(&self) -> String;
 
-    fn api_key(&self, _cx: &AppContext) -> Option<String> {
+    fn api_key(&self, _cx: &App) -> Option<String> {
         None
     }
 
@@ -130,7 +130,7 @@ pub trait LanguageModel: Send + Sync {
     fn count_tokens(
         &self,
         request: LanguageModelRequest,
-        cx: &AppContext,
+        cx: &App,
     ) -> BoxFuture<'static, Result<usize>>;
 
     fn stream_completion(
@@ -237,22 +237,22 @@ pub trait LanguageModelProvider: 'static {
     fn icon(&self) -> IconName {
         IconName::ZedAssistant
     }
-    fn provided_models(&self, cx: &AppContext) -> Vec<Arc<dyn LanguageModel>>;
-    fn load_model(&self, _model: Arc<dyn LanguageModel>, _cx: &AppContext) {}
-    fn is_authenticated(&self, cx: &AppContext) -> bool;
-    fn authenticate(&self, cx: &mut AppContext) -> Task<Result<()>>;
-    fn configuration_view(&self, cx: &mut WindowContext) -> AnyView;
-    fn must_accept_terms(&self, _cx: &AppContext) -> bool {
+    fn provided_models(&self, cx: &App) -> Vec<Arc<dyn LanguageModel>>;
+    fn load_model(&self, _model: Arc<dyn LanguageModel>, _cx: &App) {}
+    fn is_authenticated(&self, cx: &App) -> bool;
+    fn authenticate(&self, cx: &mut App) -> Task<Result<()>>;
+    fn configuration_view(&self, window: &mut Window, cx: &mut App) -> AnyView;
+    fn must_accept_terms(&self, _cx: &App) -> bool {
         false
     }
     fn render_accept_terms(
         &self,
         _view: LanguageModelProviderTosView,
-        _cx: &mut WindowContext,
+        _cx: &mut App,
     ) -> Option<AnyElement> {
         None
     }
-    fn reset_credentials(&self, cx: &mut AppContext) -> Task<Result<()>>;
+    fn reset_credentials(&self, cx: &mut App) -> Task<Result<()>>;
 }
 
 #[derive(PartialEq, Eq)]
@@ -265,12 +265,12 @@ pub enum LanguageModelProviderTosView {
 pub trait LanguageModelProviderState: 'static {
     type ObservableEntity;
 
-    fn observable_entity(&self) -> Option<gpui::Model<Self::ObservableEntity>>;
+    fn observable_entity(&self) -> Option<gpui::Entity<Self::ObservableEntity>>;
 
     fn subscribe<T: 'static>(
         &self,
-        cx: &mut gpui::ModelContext<T>,
-        callback: impl Fn(&mut T, &mut gpui::ModelContext<T>) + 'static,
+        cx: &mut gpui::Context<T>,
+        callback: impl Fn(&mut T, &mut gpui::Context<T>) + 'static,
     ) -> Option<gpui::Subscription> {
         let entity = self.observable_entity()?;
         Some(cx.observe(&entity, move |this, _, cx| {