Transaction support proporsals

[LBoullosa]

Discussions related to support transations. We will try to a POC under a OTripleS draft branch.

[LBoullosa]

For Rest API, I think transaction support should be available from controller side. We shouldn´t do it under each service because each use case may or not may require to execute the operation under a transaction that´s the reason I think a transaction should be opened for each exposed operation which requires it.