Record performance statistics for type-checking

[fredrik-bakke]

To get on top of performance related to type-checking the library, we need to have data about it first. This is useful for a multitude of reasons

• It lets us catch early if an addition significantly alters the type-checking time or memory usage of the library.
• It lets us record how performance changes with new versions of Agda, or when we change the type-checking set-up.
• it gives pointers to possibly problematic constructions that we may want to give extra attention.
• It lets us record how the type-checking time changes as the library grows.

Agda has some built-in functionality for performance debugging. I think this should be more than enough for our use case:

• https://agda.readthedocs.io/en/latest/tools/performance.html
  A big question is how reliable GitHub actions is with performance debugging.

Related to #985.