R1:046888ac2e56

In Herald, save applied transaction PHIDs in the transcript and display them in the UI

Summary:
Ref T13283. Since D14575, we already pass applied transactions to Herald, but they exist only as a backwards compatibility layer and have no upstream callsites.

Save the applied transaction PHIDs as part of the object transcript, and show them in the UI.

Test Plan:
- Viewed a modern transcript, saw a list of transactions.
- Viewed an older transcript, saw nothing (since there were no transactions in the…