Commit All Mode (#24293)

- **Base diffs on uncommitted changes**
- **Show added files in project diff view**
- **Fix git panel optimism**
- **boop**
- **Co-Authored-By: Cole <cole@zed.dev>**
- **Fix commit (all) buttons state**
- **WIP**
- **WIP: commit all mode**

Closes #ISSUE

Release Notes:

- N/A

crates/ui/src/components/icon.rs

@@ -164,6 +164,7 @@ pub enum IconName {
     ChevronRight,
     ChevronUp,
     ChevronUpDown,
+    Circle,
     Close,
     Code,
     Command,