Add deriving eq so we can test the editor/zippers

[7h3kk1d]

I'm deriving eq for a bunch of types so we can add editor tests. Mostly having them ignore ids. I figure we can use structural equality if we want id checks for now.

I pulled out the parser tests (https://github.com/hazelgrove/hazel/pull/1411) since we don't need this to do them.