Helpers to allow getting referencies and definitions

Allows to write like following:

TypeReference type1_ref = TypeRef.Of<Thread>(module);
TypeDefinition type1_def = TypeDef.Of(field_ref);
TypeDefinition type2_def = TypeDef.Of(variable_ref);
TypeDefinition type3_def = TypeDef.Of(parameter_ref);

MethodReference method1_ref = MethodRef.Of(module, Thread.BeginCriticalRegion);
MethodReference method2_ref = MethodDef.Of(module, Thread.BeginCriticalRegion);