Fix global pause menu so that it appropriately disables buttons on certain pages

[justinpanagakis-panstack]

When you're in the Level Builder and you press pause, it doesn't make sense to be able to click Level Builder again, so it should be greyed out.

Acceptance Criteria:

• Greyed out options for their own page (i.e. /levelBuilder and Level Builder)
  • Level Builder
  • Level Select
  • Settings