[WIP] Wakatime improvements

[jared-hughes]

TODO:

• [ ] Run the apiKeyValid regex on the main page (so users don't have to wait 120 seconds). - Or, do a heartbeat as soon as the api key is changed.
• [ ] Fix in Firefox.
• [ ] Avoid double-listen on disable re-enable
• [ ] Revert short intervals

Done:

• [x] Cache failed waka requests until online
• [x] Don't disable extension on auth error
• [x] Include DesModder version and stuff in user-agent
• [x] Remove idb-keyval in favor of idb (one less package import). idb-keyval is currently only used for replacement caching

Future PR: wakatime domain as optional permission.