Add support for anoma-encode builtin

[paulcadman]

This PR adds support for the anoma-encode builtin:

builtin anoma-encode
axiom anomaEncode : {A : Type} -> A -> Nat

In the backend this is compiled to a call to the Anoma / nockma stdlib jam function.

This PR also contains:

• An implementation of the jam function in Haskell. This is used in the Nockma evaluator.
• Unit tests for jam
• A benchmark for jam applied to the Anoma / nockma stdlib.

Benchmark results:

$ juvixbench -p 'Jam'
All
  Nockma
    Jam
      jam stdlib: OK
        109  ms ± 6.2 ms