Add DataEngine deltas buffering until F_LAST flag

[davidsblom]

Pull Request

Buffer deltas until the F_LAST flag is set for a delta. This option is configurable and disabled by default to keep the current behavior.

Fixes #1578

Type of change

Delete options that are not relevant.

• [x] New feature (non-breaking change which adds functionality)

How has this change been tested?

Adding unit tests