Port CTLs

[Sladuca]

Motivation

Need CTLs to do multi-stark config with memories

Changes

• added cross_table_lookup module
• split get_challenges into variants with/without CTLs
• split prove into variants with/without CTLs with common prove_single_table method
• split verify into variants with/without CTLs
• updated existing tests to use prove_no_ctl instead of prove and they work.

NOTE: no test of the CTLs themselves was performed, as it depends on a proper multi-stark setup. In starky2, this was done with AllStark, but here we plan on doing something else.