Updates the message to use the type or ValueDecl instead of this on previous 'Found this candidate' messages
Note: doees not yet change all test cases so more tests are failing
Improve Diagnostic message on overload ambiguitiy
Remove messages that say 'found this candidate' in favour of providing the type for the candidate to aid in selection when the candidates are presented in a dialogue window.
Fix more tests
Extension binding and resolution of inherited protocols uses a more primitive
'declaration' based lookup that resolves a TypeRepr directly to a set of
NominalTypeDecls.
This lookup differs from type resolution in a few subtle ways, namely the
handling of ambiguity. In particular, if there are multiple declarations
with the same name, the primitive lookup returns all of them, since it
cannot perform the full ambiguity check done in type resolution, which
looks at typealias underlying types.
However, in the case where the multiple results are all nominal types, we
can definitely fail the 'decl' name lookup right away.
