Stt 913 enter consensus comments prim sec

In working this story, there were a good number of additions that Allie and I added to the description outlining behavior based on the role the SRP member plays relative to the state of the CSR.

These updates have been reflected in the changes to the CSR update endpoint and associated tests. You will also find some additions to the validate_csr_state_change_service and tests based on STT-913 and allowed state changes that will be supported in STT-914. These changes were included in this MR as I wasn't sure or not I would need to implement some defensive protections in the update endpoint to prevent updates from being performed on a finalized CSR. For now, those protections have been left in the endpoint as a commented out TODO item for future consideration.