feat(editor): Add folding, navigation, editing and window shortcuts (#153)

Editing and folding
- Move Caret to Code Block Start / End with Selection, Auto-Indent Lines,
  Move Element Left / Right (swaps call arguments, parameters and list
  entries).
- Fold Code Block folds the {...} block around the caret; Expand to Level
  and Expand All to Level 1-5.
- Custom folding regions (//region, #region, <editor-fold>) fold to their
  description; Navigate > Custom Folding lists them.
- Error Description shows the problems at the caret; Next / Previous
  Highlighted Usage steps through usage highlights.
- Editor tooltips stay below the editor's top edge, so hints on the first
  lines no longer hide under the tab bar.

Navigation, project and run
- Navigate > File Path lists the file and its folders to reveal in the file
  manager.
- Copy... (F5) opens the Copy dialog for the selection or the open file; the
  project view's Refactor submenu gets Copy File.
- Debug... chooses a configuration to debug; Quick Evaluate Expression shows
  the selection's value in an expandable hint.
- Inspect Current File runs the inspection without the scope dialog.
- Surround with Live Template lists only $SELECTION$ templates; Java gets
  Callable, read / write lock and iterate templates.

Windows
- Stretch the active tool window left / right / up / down, Restore Default
  Layout, Go to Next / Previous Splitter, Close Active Tab on a second key,
  Stop Background Processes.

All actions have default shortcuts in both keymaps, VS Code preset entries,
main menu items and Chinese translations.

Project view and Keymap settings
- Project view Options: Sort by Name / Type / Modification Time (also in
  Find Action).
- Settings > Keymap: Add Mouse Shortcut records a side-button click with
  modifiers and checks conflicts like keyboard shortcuts.
- Folding: Expand to Level / Expand All to Level 1-5.

src/features/settings/keymap/Keymap.module.css

@@ -122,6 +122,19 @@
 }
 
 /* recorder */
+.mousePad {
+  display: flex;
+  align-items: center;
+  justify-content: center;
+  height: 72px;
+  padding: 0 12px;
+  border-radius: var(--radius-small);
+  box-shadow: inset 0 0 0 1px var(--border-strong);
+  color: var(--fg-emphasis);
+  text-align: center;
+  cursor: default;
+  user-select: none;
+}
 .recorder {
   display: flex;
   align-items: center;