TransactionTracing: Introduce FlingerDataMapper

Allow the proto parser to handle dependencies
that are external to layer via a clear interface.
This is needed to make sure the parser can map
handles to ids, get buffer info from cached buffers
or inject fake buffers in transactions to recreate
the layer's internal state.

Test: presubmit
Bug: 200284593

Change-Id: I830048a560945cce088d7276e764c953f408e0d3