Backup: Restore archive flag from YAML files

[lastzero]

Follow up issue for #567

[alexislefebvre]

Is some other data missing from YAML backups?

[lastzero]

While the archive flag should be in the YAML file, it might be reset while indexing - otherwise, the file would be skipped as archived files will be skipped. So it's an edge case I need to investigate again. Not 100% clear if the file should be put in archive, or skipped right away. Trying to avoid too much complexity here.

[lastzero]

@alexislefebvre Had to change quite a few details to make this work. We're now keeping archived files updated in the index as well. Shouldn't be too bad as you can now delete photos you don't want. That wasn't possible previously.

In addition, photo quality and time zone have been added to the YAML backups.