Add user-visible output for remote operations (#25849)

This PR adds toasts for reporting success and errors from remote git
operations. This PR also adds a focus handle to notifications, in
anticipation of making them keyboard accessible.

Release Notes:

- N/A

---------

Co-authored-by: julia <julia@zed.dev>

crates/git_ui/src/git_ui.rs

@@ -11,6 +11,7 @@ pub mod git_panel;
 mod git_panel_settings;
 pub mod picker_prompt;
 pub mod project_diff;
+mod remote_output_toast;
 pub mod repository_selector;
 
 pub fn init(cx: &mut App) {