[FEATURE_REQUEST] Filter already set tags from tag list

[rYR79435]

Is your feature request related to a problem? Please describe.
When I assign a tag to a book, a list of existing tags is displayed. That list contains tags which have already been assigned to that book. Given that selecting a tag a second time doesn't add it to the book a second time, it is redundant to display it as a choice.

Describe the solution you'd like
When assigning tags to a book, remove already assigned tags from the list of all existing tags.

[mateusz-bak]

Are you able to handle this @apobrt ?

[th8m0z]

I can also handle this

[mateusz-bak]

Alright, check with @apobrt then.

[th8m0z]

Right now, when testing on the Android emulator, the tags feature seems to be broken.
The addNewTag function throws because the tag is empty.

I'm assuming the expected behaviour would be, that the user can add their own tags?

[th8m0z]

Here is a short video displaying the problem:

shortened_tag_bug.1.mp4

[mateusz-bak]

There was a new controller that was overwriting original tags controller. I removed it and now adding tags works, you can rebase. #430

[mateusz-bak]

@th8m0z how is the work going?

[th8m0z]

Should be done in the next couple of days! @mateusz-bak

[onbreadassist]

Is the issue fixed ?