Implement Technology Menu

[BrickPi]

• Implements the Technology Menu
• Adds _make_modifier_effect_tooltip for single modifiers

[Hop311]

Also you'll probably have to rebase onto master to account for the submodule already being updated

[Hop311]

Also needs for techs:

• Allow <building>
• Activate: <good> (based on output of production type of enabled buildings)
• Allows construction of <unit>
• Changes unit appearance (when optional unit_variant is set)

And for inventions:

• Allows <crime>
• Allows construction of <unit>
• Allows <building>
• Activate: <good> (based on output of production type of enabled buildings)
• Can use Gas Attack / Can defend against Gas Attack