* Update the REST API specification
This patch updates the REST API spefication in JSON files to better encode deprecated entities,
to improve specification of URL paths, and to open up the schema for future extensions.
Notably, it changes the `paths` from a list of strings to a list of objects, where each
particular object encodes all the information for this particular path: the `parts` and the `methods`.
Among the benefits of this approach is eg. encoding the difference between using the `PUT` and `POST`
methods in the Index API, to either use a specific document ID, or let Elasticsearch generate one.
Also `documentation` becomes an object that supports an `url` and also a `description` which is a
new field.
* Adapt YAML runner to new REST API specification format
The logic for choosing the path to use when running tests has been
simplified, as a consequence of the path parts being listed under each
path in the spec. The special case for create and index has been removed.
Also the parsing code has been hardened so that errors are thrown earlier
when the structure of the spec differs from what expected, and their
error messages should be more helpful.
* introduce state to the REST API specification
* change state over to stability
* CCR is no GA updated to stable
* SQL is now GA so marked as stable
* Introduce `internal` as state for API's, marks stable in terms of lifetime but unstable in terms of guarantees on its output format since it exposes internal representations
* make setting a wrong stability value, or not setting it at all an error that causes the YAML test suite to fail
* update spec files to be explicit about their stability state
* Document the fact that stability needs to be defined
Otherwise the YAML test runner will fail (with a nice exception message)
* address check style violations
* update rest spec unit tests to include stability
* found one more test spec file not declaring stability, made sure stability appears after documentation everywhere
* cluster.state is stable, mark response in some way to denote its a key value format that can be changed during minors
* mark data frame API's as beta
* remove internal and private as states for an API
* removed the wrong enum values in the Stability Enum in the previous commit
(cherry picked from commit 61c34bbd92f8f7e5f22fa411c6b682b0ebd8a99d)
* Documents the new deprecations options on the rest-api-spec
Relates #41439#38613#35262
* remove reference to path now that #41452 is merged, also fixed missing a comma rendering the example json invalid
* removed one more instance of path
* make sure json examples are self contained and not excerpts
(cherry picked from commit 4430f99750a3bf98373d69d2be59d71475c7aaad)
Luca Cavanna
Martijn Laarman
Isabel Drost-Fromm
Honza Král
Chris Mattmann
Clinton Gormley
Karel Minarik