Failing tests

[Iluvmagick]

This is a meta-issue for all the tests I've found failing on current master as of time of [this issue's] creation. Each of theses is likely to be fixed in it's own issue. Please mark each one as completed when fixed.

• [x] blueprint_algebra_fields_plonk_exponentiation_test
• [x] blueprint_algebra_curves_plonk_variable_base_scalar_mul_test
• [x] blueprint_algebra_curves_plonk_decomposed_variable_base_scalar_mul_test
• [x] blueprint_hashes_plonk_poseidon_test -- no copy constraints.
• [ ] blueprint_algebra_fields_plonk_non_native_multiplication_test
• [ ] blueprint_non_native_plonk_scalar_non_native_range_test
• [x] blueprint_algebra_fields_plonk_sqrt_test -- interfaces haven't been updated for ages.
• [ ] blueprint_hashes_plonk_sha512_test -- is partially commented, unsure how much actually works.
• [ ] blueprint_hashes_plonk_sha512_process_test -- very likely not enough constraints, currently disconnected.
• [ ] blueprint_hashes_plonk_sha256_test -- disconnected
• [ ] blueprint_hashes_plonk_sha256_process_test -- disconnected
• [ ] blueprint_hashes_plonk_decomposition_test -- no copy constraints and broken.
• [x] blueprint_non_native_plonk_add_mul_zkllvm_compatible_test -- missing include.

[Iluvmagick]

blueprint_algebra_curves_plonk_decomposed_variable_base_scalar_mul_test is a wontfix.

[Iluvmagick]

Poseidon might be working, need someone to check; added some copy constraints to it.