Upgrade to latest version of PouchDB (current adapter)

[latin-panda]

Describe the issue
PouchDB recently released v9.X, upgrade CHT's PouchDB from v7.x to 9.x.

[lorerod]

Moved to 4.15.0 so as not to hold up the release.

[latin-panda]

The team is resuming the development this week but it won't make it to this release, so moving it to 4.16.0

[latin-panda]

Pausing this until the team reorganizes and prioritizes it again.

When this upgrade is complete, it'd be good to run Apdex Automation to compare performance between master and the upgrade branch in low-end devices.
There are some Apdex automation settings ready for the default config that can be used. Also, consider running the Apdex in another configuration used in production. And manual testing for the volume of data (queries, indexing, saving on large dbs)

The scalability test and E2Es, unit tests, and Integration tests should pass. There is a draft PR with a bit done, unit tests are passing but need more work as e2e is failing.