Synchronization for new tags on notebook entries

[scottbell]

Is your feature request related to a problem? Please describe.
Currently we don't have a way to know that an annotation has been created for a particular domain object when using a persistence store like CouchDB. Because of this, users watching remote notebooks aren't notified when new tags are created.

Describe the solution you'd like
Per a discussion with @akhenry, create a new field called annotationModified for domain objects. UIs can observe this field, and when the field changes, they can initiate a search for the new annotation.

Describe alternatives you've considered

• add include_docs to include JSON of new items over the CouchDB change feed - means more traffic per client
• add a new SharedWorker that opens a separate connection to CouchDB. It would use a special _selector filter to reduce traffic from 👆. We’d need to use feed=continuous (or longpoll) though as SSEs can’t take a selector.

Additional context
Note the existing CouchDB change feed only gives a keystring, which means if we need to know a particular annotation has been created for a particular domain object, we’ll need to lookup each new object in the change feed in full - expensive!

[scottbell]

Testing instructions:

• Open two browser implementations (e.g., Firefox & Chrome)
• Point them both to the same OpenMCT instance running CouchDB as its persistence store
• Create a new notebook and navigate to this using both browsers
• Create an entry in Firefox, observe it appears in Chrome "live"
• Create a tag in Firefox for the entry, observe the tag appear in Chrome "live"
• Delete the tag in Firefox, then add all the tags in Firefox, observe the tags delete and reappear in Chrome "live"

[jvigliotta]

Tested with Rukmini and I was able to see tags populating live and with safari (16) verified fixed 9/30/22

[unlikelyzero]

@ozyx to finalize with safari 16

[ozyx]

Verified with Safari 16 / Chrome stable. Testathon 09/30/22

Was able to create entry on chrome and see it on safari and vice versa. Was able to add a tag to the entry on chrome and see it on safari and vice versa.