GPACT v1: Segment Events need to contain root blockchain id

[drinkcoffee]

Segment events are shown to be related to a Start Event, and a root blockchain by the Crosschain Transaction Id and the Call Tree Hash.
Root events only contain the Crosschain Transaction Id (and success / fail). The root blockchain id can be inferred by which chain emitted the Root event.

However, in the signalling function, there is no way to check that the root blockchain is the correct one.

The segment event should emit its understand of the root blockchain id, which can then be checked in the signalling function.

[drinkcoffee]

This issue applies to GPACT v2 as well. As the V1 and V2 Segment events are identical, the Java SDK processing is common code. As such, this issue needs to be resolved simultaneously for GPACT v1 and V2.

[drinkcoffee]

Issue resolved by merged PR