Add physical synchronizer id to periodic topology snapshot metadata

[thibault-da]

We need the physical synchronizer Id the snapshot was taken from to correctly validate it in canton CI tests.
This PR adds it to the existing metadata file.
It also writes in a CSV-style format instead of toString the map which resulted in a not so nice to parse HashMap(key -> value) content

Pull Request Checklist

Cluster Testing

• If a cluster test is required, comment /cluster_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a hard-migration test is required (from the latest release), comment /hdm_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.
• If a logical synchronizer upgrade test is required (from canton-3.5), comment /lsu_test on this PR to request it, and ping someone with access to the DA-internal system to approve it.

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[isegall-da]

@thibault-da can you rebase on latest Splice main? We've had to make some changes following the move of Splice to CF. Thanks

[thibault-da]

@isegall-da done :)

[moritzkiefer-da]

Thanks!

[moritzkiefer-da]

nit: feels like a pretty weird csv file. instead of having headers at the top we instead have each row be a key value pair. How do you feel about making it a json file?

[thibault-da]

Sure I can make it json

[thibault-da]

Done :)

[moritzkiefer-da]

Nice thanks

[moritzkiefer-da]

CI doesn't like your change:

[info] compiling 19 Scala sources to /__w/splice/splice/apps/sv/target/scala-2.13/classes ...
Error:  /__w/splice/splice/apps/sv/src/main/scala/org/lfdecentralizedtrust/splice/sv/automation/PeriodicTopologySnapshotTrigger.scala:10:66: Unused import
Error:  import com.digitalasset.canton.topology.{PhysicalSynchronizerId, SynchronizerId}
Error:                                                                   ^
Error:  /__w/splice/splice/apps/sv/src/main/scala/org/lfdecentralizedtrust/splice/sv/automation/PeriodicTopologySnapshotTrigger.scala:14:24: Unused import
Error:  import io.circe.syntax.*
Error:                         ^
Error:  No warnings can be incurred under -Werror.
Error:  three errors found
Error:  (apps-sv / Compile / compileIncremental) Compilation failed