Users now can turn on in a viewport collections that are temporarily
hidden (eye) in the view layer.
Design task: T61327
As for the implementation, I had to decouple the visibility in the
depsgraph from the visibility in the view layer.
Also there is a "bug" that in a way was there before which is some
operators (e.g., writing a text inside of a text object, tab into edit
mode) run regardless of the visibility of the active object. The bug was
present already (with object type visibility restriction) in 2.80 so if
we decide to tackle it, can be done separately (I have a patch for it
though P1132).
Reviewed by: brecht (thank you)
Differential Revision: D5992
Use drag-only keyamp to adjust gizmos which use drag motion
to change a value. By default gizmos still activate on press.
This allows for left click select to be used with transform
without the gizmos getting in the way.
Even though this isn't necessary for right click select
it allows click events to pass through and be used by tools
which can be useful.
Resolves T63996
The popover for displaying gizmos now has options for
empty, light & camera gizmos.
Transform toggles are now checkboxes, which has the advantage that it's
more obvious they can be mixed however changing from one to another now
uses 3x clicks instead of a single click-drag action.
We might need a faster way to switch between transform types.
