Add cmd-d shortcut for (terminal) pane::SplitRight (#41139)

Add default keybinding for `pane::SplitRight` in the `Terminal` context
for all platforms.

Closes #ISSUE

Release Notes:

- Added VS Code's terminal split keybindings (`cmd` on MacOS,
`ctrl-shift-5` on Windows and Linux)

---------

Co-authored-by: dino <dinojoaocosta@gmail.com>

assets/keymaps/default-linux.json

@@ -1134,7 +1134,8 @@
       "ctrl-shift-space": "terminal::ToggleViMode",
       "ctrl-shift-r": "terminal::RerunTask",
       "ctrl-alt-r": "terminal::RerunTask",
-      "alt-t": "terminal::RerunTask"
+      "alt-t": "terminal::RerunTask",
+      "ctrl-shift-5": "pane::SplitRight"
     }
   },
   {

assets/keymaps/default-macos.json

@@ -1217,6 +1217,7 @@
       "ctrl-alt-down": "pane::SplitDown",
       "ctrl-alt-left": "pane::SplitLeft",
       "ctrl-alt-right": "pane::SplitRight",
+      "cmd-d": "pane::SplitRight",
       "cmd-alt-r": "terminal::RerunTask"
     }
   },

assets/keymaps/default-windows.json

@@ -1160,7 +1160,8 @@
       "ctrl-shift-space": "terminal::ToggleViMode",
       "ctrl-shift-r": "terminal::RerunTask",
       "ctrl-alt-r": "terminal::RerunTask",
-      "alt-t": "terminal::RerunTask"
+      "alt-t": "terminal::RerunTask",
+      "ctrl-shift-5": "pane::SplitRight"
     }
   },
   {