Add ability to hide grid per viewport

[ryevdokimov]

Implements: godotengine/godot-proposals#9037

Related to: #87793

2024-02-20.01-29-16.mp4

[Mickeon]

Huh, it makes sense in hindsight. Now it's a matter of thinking whether this is desired or not.
On a whim I'd say yes, and it doesn't look like this PR affects the existing, "global" toggle.
That menu is getting awfully tall though...

[ryevdokimov]

whether this is desired or not.

Fair. I personally use this feature along with #87793 and "View Gizmos" off to create a free flying game camera that can make micro adjustments for complex dynamic scenes while using a separate viewport that does have all of that stuff enabled to provide additional when context from a different angle when needed.

That menu is getting awfully tall though...

Agreed.

Not as bad as the editor language menu though. Personally, I think some of the menus in the editor need to be reworked in general for reasons like in: godotengine/godot-proposals#8883

[Mickeon]

I'm going to approve in principle, based on what I said before. There's nothing particularly odd about this PR. (still needs review from 3D editor team)

[akien-mga]

Didn't test, but the feature makes sense to me and the code looks straightforward.

[akien-mga]

Thanks!