Mass remove duplicate main.gd script

[grandeisa]

Most microgames don't use the main.gd script besides the signals.
My suggestion:

• Remove all main.gd scripts
• Place microgame dimensions in the microgame.tres
• Place win/lose signals in an Autoload that can be accessed by any microgame at runtime

Note that this would significantly reduce the game's size and avoid problems regarding the game having to connect to every microgame's win/lose signals individually.