Redesign the Quit Menu

[NathanLovato]

Currently it looks like that:

We could use a UI theme there. I'd also rather use styleboxes and piggyback on button and similar nodes than use custom textures.

[Siddharth1698]

Hey i can work on this. Just let me know what needs to be done

[Hansel-Dsilva]

@NathanLovato Hi. how exactly is the quit menu accessed? Currently esc button seems to be opening the upgrade menu, which I think is unintended because it doesn't really seem to change anything ingame.

[NathanLovato]

Just fixed that. You can press Esc. to open that menu