* Remove `es-test-dir` book-scoped variable
* Remove `plugins-examples-dir` book-scoped variable
* Remove `:dependencies-dir:` and `:xes-repo-dir:` book-scoped variables
- In `index.asciidoc`, two variables (`:dependencies-dir:` and `:xes-repo-dir:`) were removed.
- In `sql/index.asciidoc`, the `:sql-tests:` path was updated to fuller path
- In `esql/index.asciidoc`, the `:esql-tests:` path was updated idem
* Replace `es-repo-dir` with `es-ref-dir`
* Move `:include-xpack: true` to few files that use it, remove from index.asciidoc
adds a health section to the transform stats endpoint and implements reporting assignment, indexing/search and persistence problems, together with a overall health state.
Removes `testenv` annotations and related code. These annotations originally let you skip x-pack snippet tests in the docs. However, that's no longer possible.
Relates to #79309, #31619
Refactoring of cat transform to show more relevant information. The current cat transform shows a
lot of configuration details, however cat should show operationally useful information. This PR
changes the defaults and also adds when transform did a search last.
Fixing the naming of the HLRC values to match the ToXContent field names (i.e. the field names returned from an API call).
Also fixes the names in the _cat API as well.
closes#53946
