Currently, we have key, braille, and gesture command mappings scattered across the ChromeVox codebase

There are basically three types of mapping:
- command -> key/braille/gesture
- key/braille/gesture -> command
- key/braille/gesture -> human readable string

- command_store.js contains lots of static data about each command and is probably the place we should aim to store things in the long term

- panel.js contains a subset of the mappings with its own sub categories. We should move these out to command store

- braillemappings are in braille_command_handler.js and kbexplorer.js should probably move to command store

- key commands are scattered in key maps (key event -> command), and key util (key event -> key event human readable  string). These (next keymap), and key event -> readable string should all migrate to command store