Add key contexts for Pickers (#35665)

Closes: https://github.com/zed-industries/zed/issues/35430

Added:
- Workspace > CommandPalette
- Workspace > GitBranchSelector
- Workspace > GitRepositorySelector
- Workspace > RecentProjects
- Workspace > LanguageSelector
- Workspace > IconThemeSelector
- Workspace > ThemeSelector

Release Notes:

- Added new keymap contexts for various Pickers - CommandPalette,
GitBranchSelector, GitRepositorySelector, RecentProjects,
LanguageSelector, IconThemeSelector, ThemeSelector

crates/git_ui/src/branch_picker.rs

@@ -180,6 +180,7 @@ impl Focusable for BranchList {
 impl Render for BranchList {
     fn render(&mut self, _: &mut Window, cx: &mut Context<Self>) -> impl IntoElement {
         v_flex()
+            .key_context("GitBranchSelector")
             .w(self.width)
             .on_modifiers_changed(cx.listener(Self::handle_modifiers_changed))
             .child(self.picker.clone())

crates/git_ui/src/repository_selector.rs

@@ -109,7 +109,10 @@ impl Focusable for RepositorySelector {
 
 impl Render for RepositorySelector {
     fn render(&mut self, _window: &mut Window, _cx: &mut Context<Self>) -> impl IntoElement {
-        div().w(self.width).child(self.picker.clone())
+        div()
+            .key_context("GitRepositorySelector")
+            .w(self.width)
+            .child(self.picker.clone())
     }
 }