[Rust] Add the ability to return user-defined error from initialization/procedures

[gitbuda]

E.g. define_procedure! returns rsmgp::result::Result which holds rsmgp::result::Error which is a finite set of errors. Figure out a way how an arbitrary error could be returned. At the moment, one way of dealing with the errors is to use panic! because the Memgraph engine will catch the panic.

Please take a look under, e.g., this PR #113 for a detailed example.