The High Level REST Client's documentation suggested that users should
use the Low Level REST Client for index management activities. This
change removes that suggestion because the high level REST client
supports those APIs now.
This also changes the examples in the migration docs to that still use
the Low Level REST Client to use the non-deprecated varieats of
`performRequest`.
The current "Building Queries" and "Building Aggregations" pages are
located under the "Supported Apis" section because they are linked to
the "Search API" page.
It should instead be in a dedicated section: this commit adds a new
"Using Java Builders" section and renames few filenames in favor of
more meaningful names.
By making RestHighLevelClient Closeable, its close method will close the internal low-level REST client instance by default, which simplifies the way most users interact with the high-level client.
Its constructor accepts now a RestClientBuilder, which clarifies that the low-level REST client is internally created and managed.
It is still possible to provide an already built `RestClient` instance, but that can only be done by subclassing `RestHighLevelClient` and calling the protected constructor that accepts a `RestClient`. In such case a consumer has also to be provided, which controls what has to be done when the high-level client gets done.
Closes#26086
Nik Everett
Tanguy Leroux
Luca Cavanna