Freeze and unfreeze toolbar along with other windows.

[JacksonRG]

Closes #4255

Issue:
When freezing the view, toolbar could still be dragged around.

Fix:
Toggle toolBar.movable along with the other dock widgets.

[ferdnyc]

@JacksonRG Makes sense to me! The only concern I have is that freezing the view while the toolbar is floating makes it non-movable. (Which isn't the case with a floated dock, because it's still a window that can be dragged by its titlebar.)

So I wonder if maybe there should be a check of toolBar.floating, first, before it's potentially frozen? Just so we don't stick people with any non-draggable screen elements.

And then we'd want to link the movability to the floating status, so that it freezes once it gets docked (if the interface is frozen)... actually, I came up with some things, I'll open a PR against this branch for you to look at.

[JacksonRG]

@ferdnyc
Good thinking! I have window dragging bound to a key, so I hadn't noticed. That's a reminder for me to get out of my window manager occasionally.

[ferdnyc]

@JacksonRG Heh. Yeah, GNOME Shell can drag any window (or other onscreen element) using Super+LMB, but that's cheating!

[ferdnyc]

Once the CI build finishes, I'll go ahead and merge this.

[JacksonRG]

Once the CI build finishes, I'll go ahead and merge this.
Ty, I was about to merge on Friday, but had merge conflicts for some reason.

[ferdnyc]

@JacksonRG Yeah, I had to do a little history rewriting to get the post-my-PR-merge branch properly rebased on top of current develop and mergeable, but I eventually sorted it out. (Hopefully, we'll see what develop's history looks like now that it's merged.)

[ferdnyc]

Huh. Looks fine, actually.

Well, cool.