Implement album creation

[Mikescops]

As a user I want to be able to create an album from a selection made (see #83) or from a button "Create new album" on the UI.

As a user I should also be able to add more files to a previously created album.

[skjnldsv]

cc @jancborchardt

[jancborchardt]

Yes, this should be possible, however this is probably something a bit further in the future due to us handling photos as files in the filesystem? What do you think @skjnldsv @rullzer @Mikescops?

[Mikescops]

I don't know what kind of storage we have access too, but if we can have a mysql table, should be fine

[wein-geist]

In my post on the forum, I showed a possible implementations on this feature. I suggest the following options in the context menu:

• Add selection to existing album
• Create new album from selection
• Create separate albums from folders

The last one is when you have already some folder structure, in my case first level a folder per year, sub folders are then events, vacations, etc. It would be nice to bulk create albums from selected folders.
If it is not wanted to have a folder structure in the Photos app, it could be integrated in the context menu in the Files view.

I think however, this necessitates the implementation of #120 , because it does not make sense when folders and albums are not separated.