Multiplayer menu is a mess

[jwrober]

Is your feature request related to a problem? Please describe.
Right now we have this disjointed mutliplayer menu that has a mismash of items that some have to do with actual multipayer games and some that don't or are for a very specific ruleset (warciv).

Describe the solution you'd like
There are a few options.

1. (the easiest) is to simply hide the menu by default and then allow it to be shown with a check box on the interface tab of the local options dialog box. Then don't do anything with the menu, we just sort of make it go away

2. Evaluate what items on the menu should move to another menu. Such as the "delayed go to" options might be good to move to the unit menu as well as the "default action..." menu items.

3. Look more closely at the rest and see what we can do about them. The items specifically for trade route planning are for the WarCiv rules, maybe we do a menu break with a title or something to call that out, or do something more with trade planning in general for the rules that support trade routes (which is pretty much all of the shipped rules)

Describe alternatives you've considered
See above, at least 3 different ways to handle this menu

Additional context
None