Disable ESC when level complete screen shows up

[bchantech]

After the timer runs out and the level complete screen shows up you can press ESC and save and quit to menu. When resuming, the game softlocks.

[ShamblesSM]

While UI2 is planned and the level complete dialog box is planned to be removed once UI2 resumes development, will be keeping this issue open as that would technically resolve this issue.