Feat/firmware switching

[Dewb]

Implements #163.

• serialize active firmware name in patch json
• right-click menu option under Firmware Tools to swap to alt firmwares
• teletype 5.0.0beta4 firmware as an option (teletype 4.0 is still the default)
• kria alt firmware as an option for white whale

Also corrects UTF-8 handling of firmware paths on Windows, fixing #172.