Git tweaks (#28791)

Release Notes:

- git: Add a `git_panel.sort_by_path` setting to mix untracked/tracked
files in the diff list.
- git: Remove the "•" placeholder for "Tracked". The commit button says
"Commit Tracked" still by default, and this was misinterpreted to mean
"partially staged". Hovering over the button will show you which files
are tracked (in addition to the yellow square-with-a-dot-in-it).
- Increase the default value of `expand_excerpt_lines` from 3 to 5. This
makes it faster to see more context in the git diff view.

---------

Co-authored-by: Birk Skyum <birk.skyum@pm.me>
Co-authored-by: Peter Tripp <peter@zed.dev>

Author: 3 people

assets/settings/default.json

@@ -226,7 +226,7 @@
   // Hide the values of in variables from visual display in private files
   "redact_private_values": false,
   // The default number of lines to expand excerpts in the multibuffer by.
-  "expand_excerpt_lines": 3,
+  "expand_excerpt_lines": 5,
   // Globs to match against file paths to determine if a file is private.
   "private_files": ["**/.env*", "**/*.pem", "**/*.key", "**/*.cert", "**/*.crt", "**/secrets.yml"],
   // Whether to use additional LSP queries to format (and amend) the code after
@@ -601,6 +601,13 @@
     //
     // Default: main
     "fallback_branch_name": "main",
+
+    // Whether to sort entries in the panel by path
+    // or by status (the default).
+    //
+    // Default: false
+    "sort_by_path": false,
+
     "scrollbar": {
       // When to show the scrollbar in the git panel.
       //