git: Add git stash picker (#35927)

Closes #ISSUE

This PR continues work from #32821 by adding a stash entry picker for
pop/drop operations. Additionally, the stash pop action in the git panel
is now disabled when no stash entries exist, preventing error logs from
attempted pops on empty stashes.

Preview:

<img width="1920" height="1256" alt="Screenshot From 2025-09-11
14-08-31"
src="https://github.com/user-attachments/assets/b2f32974-8c69-4e50-8951-24ab2cf93c12"
/>

<img width="1920" height="1256" alt="Screenshot From 2025-09-11
14-08-12"
src="https://github.com/user-attachments/assets/992ce237-43c9-456e-979c-c2e2149d633e"
/>



Release Notes:

- Added a stash picker to pop and drop a specific stash entry
- Disabled the stash pop action on the git panel when no stash entries
exist
- Added git stash apply command
- Added git stash drop command

crates/git/src/git.rs

@@ -3,6 +3,7 @@ pub mod commit;
 mod hosting_provider;
 mod remote;
 pub mod repository;
+pub mod stash;
 pub mod status;
 
 pub use crate::hosting_provider::*;
@@ -59,6 +60,8 @@ actions!(
         StashAll,
         /// Pops the most recent stash.
         StashPop,
+        /// Apply the most recent stash.
+        StashApply,
         /// Restores all tracked files to their last committed state.
         RestoreTrackedFiles,
         /// Moves all untracked files to trash.