feat: Make toolbox and flyout focusable (diff PR against original reverted PR)#7

BenHenning wants to merge 12 commits intomake-toolbox-and-flyout-focusableBenHenning/blockly:make-toolbox-and-flyout-focusablefrom

make-toolbox-and-flyout-focusable-roll-forwardBenHenning/blockly:make-toolbox-and-flyout-focusable-roll-forwardCopy head branch name to clipboard