Setting to show/hide terminal title (#8559)

This PR adds settings for hiding title (breadcrumbs) from the terminal
toolbar. If the title is hidden, the toolbar disappears completely.

Example:

```json
"terminal": {
  "toolbar": {
    "title": true,
  }
}
```

[The PR that added the "toolbar"
setting](https://github.com/zed-industries/zed/pull/7338) didn't affect
toolbars of the terminals that are placed in the editor pane. This PR
fixes that.


Release Notes:

- Added support for configuring the terminal toolbar ([8125](https://github.com/zed-industries/zed/issues/8125))

crates/terminal_view/src/terminal_view.rs

@@ -13,6 +13,7 @@ use gpui::{
 use language::Bias;
 use persistence::TERMINAL_DB;
 use project::{search::SearchQuery, Fs, LocalWorktree, Metadata, Project};
+use settings::SettingsStore;
 use terminal::{
     alacritty_terminal::{
         index::Point,
@@ -90,6 +91,7 @@ pub struct TerminalView {
     blink_epoch: usize,
     can_navigate_to_selected_word: bool,
     workspace_id: WorkspaceId,
+    show_title: bool,
     _subscriptions: Vec<Subscription>,
     _terminal_subscriptions: Vec<Subscription>,
 }
@@ -165,7 +167,12 @@ impl TerminalView {
             blink_epoch: 0,
             can_navigate_to_selected_word: false,
             workspace_id,
-            _subscriptions: vec![focus_in, focus_out],
+            show_title: TerminalSettings::get_global(cx).toolbar.title,
+            _subscriptions: vec![
+                focus_in,
+                focus_out,
+                cx.observe_global::<SettingsStore>(Self::settings_changed),
+            ],
             _terminal_subscriptions: terminal_subscriptions,
         }
     }
@@ -208,6 +215,12 @@ impl TerminalView {
         self.context_menu = Some((context_menu, position, subscription));
     }
 
+    fn settings_changed(&mut self, cx: &mut ViewContext<Self>) {
+        let settings = TerminalSettings::get_global(cx);
+        self.show_title = settings.toolbar.title;
+        cx.notify();
+    }
+
     fn show_character_palette(&mut self, _: &ShowCharacterPalette, cx: &mut ViewContext<Self>) {
         if !self
             .terminal
@@ -832,7 +845,11 @@ impl Item for TerminalView {
     }
 
     fn breadcrumb_location(&self) -> ToolbarItemLocation {
-        ToolbarItemLocation::PrimaryLeft
+        if self.show_title {
+            ToolbarItemLocation::PrimaryLeft
+        } else {
+            ToolbarItemLocation::Hidden
+        }
     }
 
     fn breadcrumbs(&self, _: &theme::Theme, cx: &AppContext) -> Option<Vec<BreadcrumbText>> {