feat(developer): rework touch layout editor

* Restrucure touch layout editor to make space for additional gesture
  types:
  * Move control bar to right hand side
  * Move key cap edits to control bar.
* Adds flick and multitap gestures:
  * Adds buttons to add longpress keys, flicks or multitaps.
* Adds Unicode value boxes which mirror the key cap text box.
* Updates key width values in real time when resizing
* Maintain selected key as far as possible across layer switch, platform
  switch and presentation view switch.
* Starts to split 'special' key cap icons from normal key caps.