Map TeamForCapella commits to Git commits in backup script

[MoritzWeber0]

This option is only available for TeamForCapella 7.0.0 since the relevant features have been added in this version.

Change the backup script to map TeamForCapella commits to Git commits in a 1:1 mode.

1. Run the importer application and export the commit history since the last Git commit (without project export)
2. For each commit, run the importer application and create a new Git commit with the commit information.
3. Push the commits.

The title of the commit should be the first line of the commit message in TeamForCapella. Other lines should be added to the commit description. The commit author should be the username from TeamForCapella.