Update to 1.14 and flexibility upgrades

[Pyrofab]

• Most project attributes have been moved to properties. Properties have been rearranged, the ones that are changed most often are at the top of the file. Note: I moved the project name to a property, intellij's analysis trips over it sometimes. I can revert that if you want.
• The fabric.mod.json file has been updated to version 1, and more attributes are filled in by gradle.
• License headers for GPL and LGPL have been added, with a templated copyright owner.
• The group domain has been changed from com.github to io.github, as that's the website most of us actually own.
• The mixin json files have been prepended with mixins., to 1) make their purpose more explicit and 2) let them be picked up by the minecraft dev plugin.

[UpcraftLP]

5 GB is way too much, 2 at most.