Implement CoreTypeConcrete::Bytes31 return type

[pefontana]

Implement the parse result for CoreTypeConcrete::Bytes31 https://github.com/lambdaclass/cairo_native/blob/ddfd28217c10f7202a03f10234f0a19113c46904/src/executor.rs#L786

We should be able to run the bytes31_ret.cairo test https://github.com/lambdaclass/cairo_native/blob/e89d38ad2f01bbd85c9f9de0b37841ac98661b50/tests/tests/cases.rs#L113

[greged93]

hey @pefontana, I'm down to try this if is possible

[raizo07]

Hello @pefontana I'd like to work on this

[pefontana]

Hi @raizo07 ! Sorry, I am currently implementing it! But if you want to take another CoreTypeConcrete return type, you can ask us and implement it!