Improve the design of the menu

[shannonturner]

Kinda related to #81, although the menu looks much nicer in v6 and higher than in previous versions, it's starting to get a little cluttered.

The problem gets worse as I add more features too, like in v7.1.1 and v7.2.

I think I'll have to prioritize improving the menu.

[shannonturner]

This has also been requested by a few different users over the years, most recently by email:

Firstly, Metro Map Maker is great, but its UI feels kind of clunky. Maybe you can move the tools (Draw, Station, Erase, and Style to the left; and instead of expanding the options (like line color etc.) downwards, a popout menu on the right. Here is an example: