The following updates were made:
* Add deprecation warnings to `RestUpdateAction`, plus a test in `RestUpdateActionTests`.
* Deprecate relevant methods on the Java HLRC requests/ responses.
* Add HLRC integration tests for the typed APIs.
* Update documentation (for both the REST API and Java HLRC).
* Fix failing integration tests.
Because of an earlier PR, the REST yml tests were already updated (one version without types, and another legacy version that retains types).
This further applies the pattern set in #34125 to reduce copy-and-paste
in the single document CRUD portion of the High Level REST Client docs.
It also adds line wraps to snippets that are too wide to fit into the box
when rendered in the docs, following up on the work started in #34163.
Some features have been deprecated since `6.0` like the `_parent` field or the
ability to have multiple types per index. This allows to remove quite some
code, which in-turn will hopefully make it easier to proceed with the removal
of types.
Julie Tibshirani
Nik Everett
Adrien Grand
Luca Cavanna