git_ui: Prevent button overflow due to long names (#25940)

- Fix component preview widths for git panel
- Fix buttons getting pushed off the screen in git  panel

Release Notes:

- N/A

---------

Co-authored-by: Mikayla Maki <mikayla.c.maki@gmail.com>

crates/component_preview/src/component_preview.rs

@@ -226,3 +226,7 @@ impl Item for ComponentPreview {
         f(*event)
     }
 }
+
+// TODO: impl serializable item for component preview so it will restore with the workspace
+// ref: https://github.com/zed-industries/zed/blob/32201ac70a501e63dfa2ade9c00f85aea2d4dd94/crates/image_viewer/src/image_viewer.rs#L199
+// Use `ImageViewer` as a model for how to do it, except it'll be even simpler