policy-monitor: data flow should be stopped on transfer completion

[ndr-brt]

Feature Request

When the TransferProcess gets completed by the policy monitor, it should terminate the data flow accordingly.

This should be done either on the DataFlowControllerRegistry that need to find the correct DataFlowController and terminate the flow, or in the "deprovisioning" phase.

The only implementation we need to put in place would be for the ProviderPushTransferDataFlowController, where the terminate call should be done either:

• on the previous choosed dataplane
• on every dataplane that can handle that dataflow.
  likely the second one is the correct one, because the dataplane that started the dataflow could have been stopped and replaced with another one,

The consumer-pull flow does not need a terminate method because the token expiration will already do the job.

Which Areas Would Be Affected?

e.g., DPF, CI, build, transfer, etc.

Why Is the Feature Desired?

Are there any requirements?

Solution Proposal

If possible, provide a (brief!) solution proposal.