Implement arbitrary patch set support

Patch sets would have properties which define how they are applied and what they are etc.

Example config in Kotlin I came up with on the fly:

patchSets {
    "base" {
        "decomp"()
        "impl" {
            patchType = PatchType.FILE
        }
    }
    "feature" {
        "async" {
            "some-thing"()
            "other-thing"()
        }
    }
}

A language designed for configuration like hocon (or other options) may be better and cleaner. There may be other options and properties for patch sets as well.

This is just for book keeping so I don't forget about building out this functionality.

Start with the Kotlin configuration example in the issue and compare its proposed patch-set properties with the discussion of HOCON or other configuration options. No repository files, tests, entry points, or acceptance criteria are named, so the design and definition of done need to be established before implementation.