Update NSOpenGLView frame when switching to galaxy picker

Otherwise you can't see the title until you resize.
Use window size when initialzing galaxy picker

Since I refactored this, I had forgot that there were some
hardcoded values for the size of the view to draw, and when
you resize at the main menu, we no longer drew our subviews
correctly when you start a new game.
Don't accept user input when paused

Applies to the following:

mouse input (zoom and panning)
keyboard input (toggle state of sidebar)