Integrate Blockly keyboard controls

[tracygardner]

Already 'enabled' (technically included). Doesn't seem to break mouse behaviours so leaving on.

Various issues including:

• Focus doesn't move with block when you navigate out of view
• List blocks mutator buttons get focus and work but there is no visual focus highlight
• You have to press Tab to get to grid inputs, is that ituitive
• Focus highlight not clear on grid editors (such as color)
• Mutator buttons on custom blocks don't have focus highlight (but do work)
• We get a additional blue focus highlight around the workspace and toolbox. Not needed.
• Esc should close block comments
• Enter should edit text input blocks without having to navigate right. They technically have a nested input but the user shouldn't have to worry about that.
• Ctrl + Enter context menu on the workspace sometimes appears off screen
• Esc doesn't close block context menu
• Esc doesn't close workspace context menu
• Style toast messages to match Flock
• Add translation for toast messages