Clock refactor + Home Assistant support

[JanPetterMG]

This is a relatively large PR, but can quickly be summarized by the following three bullet points:

• Merge Small clock and Small ticking clock into one unified clock mode.
• Renamed Large ticking clock to Large clock
• Implement Home Assistant support for toggling the ticking introduced in Configure ticking in small and large clock via webapp #258

Key changes

• Renamed Large ticking clock to Large clock.
• Merged Small clock with Small ticking clock.
• Implemented Home Assistant support for clock ticking.
• Added deprecation warnings.
• Changed old .env variables to aliases.

Impact

• Existing users of the Small clock will now see ticking by default, but this can be toggled on/off as desired via the UI.
• Environment variables MODE_LARGETICKINGCLOCK and MODE_SMALLTICKINGCLOCK are now deprecated and added as aliases for the new modes.