feat: Add shortcuts for stroke and background color picker (#3318)

* feat: Add shortcuts for opening stroke and background color picker

* Use App.tsx keydown handler

* only get selectedElements if applicable (perf)

* fix tests and snaps

* reuse `appState.openMenu`

Co-authored-by: dwelle <luzar.david@gmail.com>

src/locales/en.json

@@ -101,6 +101,8 @@
     "viewMode": "View mode",
     "toggleExportColorScheme": "Toggle export color scheme",
     "share": "Share",
+    "showStroke": "Show stroke color picker",
+    "showBackground": "Show background color picker",
     "toggleTheme": "Toggle theme"
   },
   "buttons": {