## Summary
This moves code from `plugins/aiops/common` to packages. The `aiops`
plugin will from now on have only a `server` and `public` directory.
This is in preparation for additional AIOps related public APIs and to
avoid cyclic dependency problems for other consuming plugins.
- Package `@kbn/aiops-utils` was renamed to `@kbn/aiops-common`.
- For each AIOps feature a package was created:
`@kbn/aiops-change-point-detection`, `@kbn/aiops-log-pattern-analysis`
and `@kbn/aiops-log-rate-analysis`.
### Checklist
- [x] This was checked for breaking API changes and was [labeled
appropriately](https://www.elastic.co/guide/en/kibana/master/contributing.html#kibana-release-notes-process)
This PR uses [conditional
types](https://www.typescriptlang.org/docs/handbook/2/conditional-types.html)
to allow the handling of both multiple API versions within one route handler. The more tricky bit turned out
to be not the updated request body, but the response since it is an
NDJSON stream where some messages were updated. In this case also the
functions that create these messages were updated with conditional types
to be able to create a message that fits the definition of the API
version.
The API integration tests originally had these message identifiers in
the `expected` section of their `testData`. I changed that to use helper
functions that retrieve the expected messages from the stream according
to the expected version. All API integration tests are run on both
versions. The functional tests are run only on the newer version since
the UI is expected to work with version `2` only.
