Add descriptive messages to all assertions in library code for better testing and debugging

[akonior]

Suggestion: It would greatly enhance the developer experience and debuggability if descriptive messages could be added to all assertions within the library code. I our project that depends on noir-trie-proofs we have a lot of failure tests and we would like to check that specific assertion was thrown using:

#[test(should_fail_with = "<the reason for failure>")]