Gizmo subscene visibility option

[LRJiao]

Referencing #8220, this pull will create an option in view for both 2D and 3D scenes that will hide all gizmos of subscenes in addition to any current gizmo options selected.

Before toggle:

After: (Cylinder shape added in base scene for reference)

[Chaosus]

Commits needs to be squashed (see https://docs.godotengine.org/en/latest/contributing/workflow/pr_workflow.html).

[LRJiao]

Commits needs to be squashed (see https://docs.godotengine.org/en/latest/contributing/workflow/pr_workflow.html).

Squashed, thank you for letting me know.

[fire]

Gizmo subscene visibility option

This option is good feature wise, but I don't think the toggle should be in the Gizmos list. This toggle is not the same as the other toggles

What about putting Gizmo subscene visibility option beside the top level gizmos entry? Also use a check box.

[LRJiao]

Gizmo subscene visibility option

This option is good feature wise, but I don't think the toggle should be in the Gizmos list. This toggle is not the same as the other toggles

What about putting Gizmo subscene visibility option beside the top level gizmos entry? Also use a check box.

Adjusted to be a checkbox, similar to the 2D option.

[LRJiao]

Accidentally closed due to renaming, new PR is up