[Doc] Add an UpdateRequest example to Java API doc

Closes #7083.
java: QueryBuilders cleanup: remove deprecated

Related to #8667:

Some QueryBuilders have been deprecated in 1.x branches. We removed them in 2.0.

Removed
-------

* `textPhrase(...)`
* `textPhrasePrefix(...)`
* `textPhrasePrefixQuery(...)`
* `filtered(...)`
* `inQuery(...)`
* `commonTerms(...)`
* `queryString(...)`
* `simpleQueryString(...)`

Closes #8721.
[TEST] remove action names bwc layer

The bwc layer added with #7105 is not needed in master as a full cluster restart will be required, thus from 2.0 on the only supported action names are compliant to the defined conventions and don't need to be converted to the old format

Closes #8758
[DOCS] Document ActionNamesTests
[Doc] Java API: add search templates

Closes #7321.
[Doc] Java API: add information on JBoss EAP

Closes #3445.
API endpoint cluster.put_settings accepts timeout & master_timeout query parameters

Closes #8769
Add custom index.data_path and index.data_template settings
Pass IndexSettings through nodeEnv.deletShardDirectorySafe
Delete state dir for indices with custom data paths
Duh, need to actually delete the index if I expect it not to exist...
Documentation and cleanups
Remove use for File.separator