[RFC] Port of Ruby combat framework to Kotlin

[garyttierney]

While not in scope for the kotlin-experiments branch, this is something I'd still like to get some feedback on. All of the basics are there for melee + ranged, including max hit / accuracy. The DSL itself is almost a one-to-one port of what was done in Ruby, with some Kotlin specifics to make the framework more idiomatic.

See the Scimitar/Bow plugins for examples of how to configure new weapon classes and weapons. Scimitar and Bow are WeaponClass objects that are defined by melee_classes.kt and ranged_classes.kt.

[garyttierney]

My current TODO list for this (not counting the numerous @todo's scattered around the code) can be found here: https://github.com/apollo-rsps/apollo/pull/376/files#diff-4553fbd36a1d88c8c2e744f5de0cc847