Perform upgrade path testing from 1.5.2 to 1.6.0

[PaulKlauser]

Note: This work can't be done until we've finalized the database/preset work, and are ready to release a 1.6.0

1.6.0 is going to be the next production release of Vocable, and 1.5.2 was the last in 2020.

Between these versions we have some database and data handling changes, so it's going to be critical that we do upgrade path testing from 1.5.2 to 1.6.0.

Key Scenarios:

• Custom phrases and categories are retained
• Preset phrases and categories are not duplicated