repl: Add ctrl-alt-enter binding to run in place (#15743)

Release Notes:

- Added `ctrl-alt-enter` keybinding for `repl::RunInPlace`
(`ctrl-option-enter` on MacOS). Keeps your screen position and cursor in
place when running any block.

assets/keymaps/default-linux.json

@@ -479,7 +479,8 @@
   {
     "context": "Editor && jupyter && !ContextEditor",
     "bindings": {
-      "ctrl-shift-enter": "repl::Run"
+      "ctrl-shift-enter": "repl::Run",
+      "ctrl-alt-enter": "repl::RunInPlace"
     }
   },
   {

assets/keymaps/default-macos.json

@@ -178,7 +178,8 @@
   {
     "context": "Editor && jupyter && !ContextEditor",
     "bindings": {
-      "ctrl-shift-enter": "repl::Run"
+      "ctrl-shift-enter": "repl::Run",
+      "ctrl-alt-enter": "repl::RunInPlace"
     }
   },
   {