Refine ARM template usage with named templated parameters

[tadelesh]

create is ArmResourceCreateOrRepalceAsync<
  Employee,
  BaseParameter<Employee>,               // <- No need to lay out in order to get to last param
  ArmAsyncOperationheader>;   

=>

create is ArmResourceCreateOrRepalceAsync<
  Employee,
  LroHeaders = ArmAsyncOperationheader>;      

[tadelesh]

related issue and pr: https://github.com/Azure/typespec-azure/issues/105, https://github.com/Azure/typespec-azure/pull/376