Drops the boolean is_personal() wrapper in favor of matching
DriveKind::Personal/Shared at the two call sites, matching the
exhaustive-match convention already used for DriveKind elsewhere
(as_str, parse, DriveKindDto::from).
add `include_in_photo_index` and `include_in_music_index` policies
both true for default personal drive
photo is implemented
music is not yet implemented
now Drive is purely a metadata
each drive has always a root folder
this model minimize Oxicloud changes, and simplify
the Drive name is simply the folder's root's name
note: owner of Drive has more permission that an owner of the root folder