settings ui: Add missing setting elements (#39644)

Added the following settings to the UI

Editor Page - Scrollbar Section (9 settings)
- Show
- Cursors
- Git Diff
- Search Results
- Selected Text
- Selected Symbol
- Diagnostics
- Horizontal Scrollbar
- Vertical Scrollbar

 Editor Page - Minimap Section (6 settings)
- Show
- Display In
- Thumb
- Thumb Border
- Current Line Highlight
- Max Width Columns

Editor Page - Editor Behavior Section (3 settings)
- Expand Excerpt Lines
- Excerpt Context Lines
- Minimum Contrast For Highlights

 Debugger Page (7 settings)
- Stepping Granularity
- Save Breakpoints
- Timeout
- Dock
- Log DAP Communications
- Format DAP Log Messages
- Button

 Panels Page - Git Panel Section (3 settings)
- Button
- Dock
- Default Width

Collaboration Page - Experimental Section (4 settings)
- Auto Microphone Volume
- Auto Speaker Volume
- Denoise
- Legacy Audio Compatible

Release Notes:

- N/A

assets/settings/default.json

@@ -1233,8 +1233,8 @@
     "git_gutter": "tracked_files",
     /// Sets the debounce threshold (in milliseconds) after which changes are reflected in the git gutter.
     ///
-    /// Default: null
-    "gutter_debounce": null,
+    /// Default: 0
+    "gutter_debounce": 0,
     // Control whether the git blame information is shown inline,
     // in the currently focused line.
     "inline_blame": {