Organize utility functions #22

It is often difficult to find some metaprogramming utility functions for a certain job. The big issue here is that they often have somewhat different contexts in which they are defined, most notably some functions are monadic and some aren't. Nonetheless, we probably use the utility functions more than we write them, so we should optimize for findability possibly at some expense of a more complicated tree of module dependencies.

My proposal would be to make modules such as

• Reflection.Util.Term
• Reflection.Util.Telescope
• Reflection.Util.Type
  etc.

There are likely going to be lots of cross-imports between them, which would become cyclical dependencies, so more realistically we would have those modules mostly just reexport names further down the hierarchy, e.g. from Reflection.Util.Term.Monadic, to break the cycles.