Use ORM instead of SQLite SQL

[dennisguse]

We have quite a lot of code to manage three tables in a SQLite database.
One option would be to use an ORM like https://developer.android.com/jetpack/androidx/releases/room

Moreover, all DB interaction is done via ContentProvider.
This complicates the situation even further while it has the advantage that all data can be exposed to other applications.

Plan:

• OpenTracks accesses SQLite DB directly (without CustomContentProvider)
• Trim down CustomContentProvider to only provide data for Dashboard API (e.g., for OSMDashboard)
• Check if ORM/Room helps to get rid of the large amount of data handling code