feat: type equality checks should be warnings/errors

[eseidel]

    collection_methods_unrelated_type: warning
    unrelated_type_equality_checks: warning

These are (currently) the only modifications I need to make the very_good_analysis. :)

Both of these show up as infos by default, but both are always? real bugs.

e.g. collection_methods_unrelated_type

final foo = <String>{"foo"};
print(foo.contains(1));

Or unrelated_type_equality_checks:

print("foo" == 1);

Probably I should be filing a bug with the Dart SDK, since again it makes no sense to treat either of those cases as an "info" IMO.

[renancaraujo]

Fixed on 5.1.0