Add endpoints (or design a webpage) showing the status of a decentralized synchronizer

[waynecollier-da]

Operators of a decentralized Canton synchronizer, like the Global Synchronizer on Canton Network, want to be able to easily report the status of the synchronizer to application providers and validator operators. For example, they would like to report, for each node in the decentralized quorum:

• the Splice version operated by that node
• the migration ID
• the Scan endpoint
• the Sequencer endpoint
• recent uptime / availability of the Scan and Sequencer endpoints
• hash / id of the most recent version of the IP whitelist approved by the node
• hash / id of the most recent version of the approved-sv-id-values.yaml approved by the node

And for all nodes:
-all prior and approved future migration date-times
-all active synchronizers for a given DSO

The objective is for this information to be

-easily displayed on a web page
-updated automatically from the nodes, and / or from a GitHub repo (like the GSF repo) where the nodes record agreements on configuration settings.