Fix class injector abstract method handling

[WNP78]

The class injector does checking on abstract methods to match parameter names and types of implemented methods, but the ParameterInfo struct and hence the name field was removed in newer versions of IL2CPP. This is an easy fix because the IL2CPP API has a method to get the name of a parameter from the MethodInfo and index.

[ds5678]

I am in favor of simply removing the parameter name check because it's not part of the method signature.

I also think we should add a check for the return type.

@Kasuromi thoughts?

[Kasuromi]

Using the method signature is better to solve this exact issue, though we need to also see about how we'll handle ParameterInfo not being present in newer il2cpp versions.

Either way, if we switch this to use everything that is part of the method signature this would be good for merging.