Add Room migration

[OffRange]

We need to add migration from db version 3 (secure_element_database) from v1 to version 1 (keygo_database)

[OffRange]

TODOS

• Understand why seedLegacyDatabase instead of room-testing which automatically reads schemas
  • Would be logical to introduce in-memory db for testing (room3 makes this easy) + drop any custom createDatabase(version,...)
• Why not just add custom migration step to handle NOT NULL (2 -> 3)
• Why are migrations from db version 1 -> 2 -> 3 different from v1 branch
• Why dont we use a room converter to fetch the decrypted detail from the dao directly? This would mean a simpler codebase, potentially less code and less code to test. MAybe even drop specialized detail classes and just keep LegacyDetailJson
• HasLegacyDataUseCase never beeing used in a non-test scenario
• LegacyItemRepositoryImpl.state() kinda overkilled? Why not just check if file exists, elements can be found. If found, migrate then delete file if not delete rightaway
• Probably simplify LegacyImportRunner/StartLegacyDataImportUseCase and report status to the user. Show a progress screen, etc.