feat(vcs): Accept a diff change from the keyboard and step between diff files (#158)

- Accept Left Side / Accept Right Side copy the change at the caret to the
  other side of a side-by-side diff (⌃⌘→ / ⌃⌘← on macOS, Ctrl+Alt+R /
  Ctrl+Alt+A on Windows).
- Compare Next File / Compare Previous File open the neighbouring file of
  the diff chain directly (⌃⇧→ / ⌃⇧← on macOS, Alt+Shift+→ / ← on Windows).

src/platform/keymaps/intellij-macos.ts

@@ -316,6 +316,10 @@ export const intellijMacos: Record<string, string[]> = {
   "diff.nextDifference": ["F7"],
   "diff.prevDifference": ["Shift+F7"],
   "diff.jumpToSource": ["F4"],
+  "diff.applyLeftSide": ["Ctrl+Meta+Right"],
+  "diff.applyRightSide": ["Ctrl+Meta+Left"],
+  "diff.nextFile": ["Ctrl+Shift+Right"],
+  "diff.prevFile": ["Ctrl+Shift+Left"],
   // After Show Diff: ⌘D is Compare With… in the project view.
   "project.compareWith": ["Meta+D"],
   // Editing extras, image viewer (keyWhen: image focused) and Markdown editor layouts

src/platform/keymaps/intellij-windows.ts

@@ -314,6 +314,10 @@ export const intellijWindows: Record<string, string[]> = {
   "diff.nextDifference": ["F7"],
   "diff.prevDifference": ["Shift+F7"],
   "diff.jumpToSource": ["F4"],
+  "diff.applyLeftSide": ["Ctrl+Alt+R"],
+  "diff.applyRightSide": ["Ctrl+Alt+A"],
+  "diff.nextFile": ["Alt+Shift+Right"],
+  "diff.prevFile": ["Alt+Shift+Left"],
   // After Show Diff: Ctrl+D is Compare With… in the project view.
   "project.compareWith": ["Ctrl+D"],
   // Editing extras, image viewer (keyWhen: image focused) and Markdown editor layouts

src/platform/keymaps/vscode-macos.ts

@@ -324,6 +324,10 @@ export const vscodeMacos: Record<string, string[]> = {
   "markdown.previewOnly": ["Meta+Shift+V"],
   // Diff editor (VS Code: workbench.action.compareEditor.nextChange / previousChange)
   "diff.nextDifference": ["F7"],
+  "diff.applyLeftSide": [],
+  "diff.applyRightSide": [],
+  "diff.nextFile": [],
+  "diff.prevFile": [],
   "diff.prevDifference": ["Shift+F7"],
   "diff.jumpToSource": [],
   // HTTP Client / Database console: run the request or statement at the caret.