Issue Summary

Kanban Board: Add/Remove from Board functionality is not obvious enough

Steps to Reproduce

1. Login
2. Go to Kanban Board.
3. Add Stories and Remove Stories using Mass Add/Remove from Board.

Expected Results

1. For items that are added to Board, Select Checkbox is enabled and checked, regardless of Column, they are added to.
2. For items that aren't added to Board, Select Checkbox is enabled and unchecked.
3. For items that are added to different Board, Checkbox is disabled and unchecked(Same as today, no changes needed).
4. Rename Add/Remove to Board button to Add/Remove from Board
When items from group 1 are deselected and Add/Remove from Board clicked selected items are removed from the Board.
When items from group 2 are selected and Add/Remove from Board clicked selected items are added to the Board(Same as today, no changes needed).
When Items from group 1 are deselected, items from group 2 selected and Add/Remove from Board clicked board is updated respectively: deselected items are removed, selected items are added.

Actual Results

It's not clear how Add/Remove works. Dialog has too many inconsistencies and restrictions.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available