Simplify Bus Interaction

[georgwiese]

Fixes #1823

This PR cleans up our bus_interaction function and all functions that depend on it, so that columns and challenges are added when needed, instead of being passed by the caller.

I also changed the tests a bit: I removed test_data/std/bus_{permutation,lookup}_via_challenges{_ext?}.asm and instead added more realistic tests:

• test_data/std/bus_lookup.asm: Is a fixed lookup, completely analogous to lookup_via_challenges.
• test_data/std/bus_permutation.asm: Uses a permutation to connect a block machine.

[georgwiese]

Rebased onto main and pushed 32f40d0b8606dfedbb005b94a7b64d25be72d48d, which I forgot to push earlier.