Li-chan: Handle Revoked Channel Access

Tracker for changes arising from the Handled Revoked Channel Access feature.

Consistent handling of documents that users lose access to regardless of whether it was because they lost access to it as a result of document removal from all of the user's channels or because the user loses access to the channel  is important.

PRD: https://docs.google.com/document/d/14gawyt9lcHYUlCh0APUt-7V6M6Kkk0zoXi7GOfYiMLM/edit?ts=5fc86642#

API: 

Background:

• https://docs.google.com/document/d/1SSKzPeBfYoQzgA8h0Oho3joLCXVvyDoACQ10-nEBvzs/edit#

Impacted Assets: 

• SGW:
  • whatsnew
  • sync gateway's channels page http://localhost:5000/sync-gateway/2.8/learn/sync-gateway-channels.html#remove-from-channel
  • sg.yaml
  • sync-gateway-admin.yaml
  • icr-sgreplicate.adoc
  • release notes – breaking change
• CBL:
  • whatsnew
  • releasenotes api changes
  • {root-commons}

    sgw-replication.adoc

• • {root-partials}

    document-expiriation.adoc

  • {root-partials}
    replication-events.adoc

• • {module-partials}

    _attributes-module.adoc – api reference links to new/changed api option(s)

Dev Tickets:

• https://issues.couchbase.com/browse/CM-319 (SGW to CBL)
• https://issues.couchbase.com/browse/CM-451  (ISGR)
• https://issues.couchbase.com/browse/CBG-1280 

Docs Ticket:

•  Assessment: DOC-7796
• Content:  DOC-7799 (epic)