ActionButton: Add mnemonic support
Original commit message(s)
- ActionButton: Add mnemonic support
Allows to use Alt+letter to activate them.
Reason for the change
Makes it consistent with other buttons and allows for quick access.
Unfortunately changes text format to StyledText
but I don’t think we use them with external text (e.g. user names?)
Test plan
Lock screen, can now do Alt+S to switch user (will make a patch to add consistent mnemonics afterwards)