git_ui: Show author name on commits in branch picker (#36812)

See related discussion
https://github.com/zed-industries/zed/discussions/36511.

<img alt="zed"
src="https://github.com/user-attachments/assets/da7fc30d-2504-48f4-a392-7c8d5cd8acb1"
/>

Release Notes:

- Added option to show the author name in a branch picker commit
information

---------

Co-authored-by: Conrad Irwin <conrad.irwin@gmail.com>

crates/git_ui/src/commit_tooltip.rs

@@ -229,6 +229,7 @@ impl Render for CommitTooltip {
                         .into()
                 }),
             commit_timestamp: self.commit.commit_time.unix_timestamp(),
+            author_name: self.commit.author_name.clone(),
             has_parent: false,
         };