Patient Transfer Should Be Transactional

[trobanga]

At the moment, if patient data is split into multiple bundles it is possible that not all bundles are fully transferred to the RDA.
The RDA should collect the bundles and only send them to the HDS once they are complete.

To implement this, the CDA needs to tell the RDA how many bundles to expect.

This approach obviously protects only the transfer between CDA and RDA, not between RDA and its HDS.