added error messages to various unwraps

[resoluteCoder]

This PR adds error messages for the unwrap functions as follows:

• Used unwrap_or_err for functions that return results with an err.
• Used expect for functions that return an option.
• Used convention of x not found for error messages

Original reference PR: #241

[declark1]

Thanks! Just a couple of comments inline to add detector_id to the error message.

[evaline-ju]

@resoluteCoder for a first contribution maintainers have to approve the workflow - could you look into the failing linting? It can also be debugged locally with cargo clippy --all-targets --all-features -- -D warnings thanks!