Keyboard controls for overall UI

[tracygardner]

• Add keyboard controls documentation popup with full documentation of blockly keyboard controls @lawsie
• Detect OS and show appropriate modifier in docs Label keyboard controls based on platform #538 @lawsie
• Add link to keyboard controls documentation on hub from in-tool documentation @lawsie
• Make Escape work across UI
• Add Ctrl + B area menu @lawsie
• Add overlay UI for gizmos with keys when you use the Ctrl+G shortcut @lawsie
• Resize slider bar should be an area as it's useful and this will aid discovery? @lawsie
• Closing popup dialogs should return focus to a sensible visible element
• Add 'p' shortcut to play the project without switching focus from the workspace
• Ctrl + E etc should work initially from anywhere in the UI
• Users of adaptive devices need the ability to map keyboard inputs to different keys (including movement, buttons and camera)
• Focus should move to 'reload' button when it appears? Check ARIA guidelines.
• First use of Ctrl+E does focus the workspace (shortcuts work) but there is no visual focus highlight
• Ctrl+M shortcut should just navigate to main menu, not open it.
• Use iOS friendly arrow key symbols in set key block

[tracygardner]

Added support for remapping keyboard controls based on input from our lived experience consultant for use with adaptive devices.

7e8b180 c5efb7d 2bea99a 4e49859 28c9af4 69d67ad

[lawsie]

Sounds good

[tracygardner]

Improved focus for menu and modal dialogs. (Focus was being placed on hidden elements and tab didn't close the main menu.)

6b85e00 514ecc4 f25293e

[tracygardner]

Make Esc work for About modal and Colour picker

aed5a0f

[tracygardner]

'p' added as a blockly shortcut to play (reset) the project without changing focus. Ctrl+P plays the project and does change focus. Gives the user control over whether to switch to the canvas to interact. d7486f5 97f1ed0

[tracygardner]

Closing modals returns focus to the menu and improved escape handling #449