Implement the UI part of Profile/Settings/Showcase:
- Communities/Accounts/Collectibles/Assets tabs
- drag and drop of items between "hidden" and "in showcase" sections
- ability to set individual items' visibility
- persistency (showcase saved across restarts), not exposed yet due to
missing backend API
Closes#9936
- the goal of this PR is to get some bsais UI building blocks done for
the followup PRs
- the order of showcase tabs now is:
Communities/Accounts/Collectibles/Assets
- there will be further changes to accomodate for different types of
backend models as those get developed (for other users' profiles)
Fixes#9664
Khushboo Mehta
Anthony Laibe
Lukáš Tinkl