Error output: Add line number & relation

[Laschoking]

When receiving an error like:
error: Overloading of predicate names by arity is currently not supported.
it would be good, to output the line number and relation which caused he error.

[Laschoking]

Another case is when I try to output a relation that does not exist (i.e. because of a typo), I receive the imprecise error message :
thread 'main' panicked at nemo/src/execution/execution_engine.rs:783:26: all predicates should have a type by now

[monsterkrampe]

Likely addressed in #455.