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
Move the JDBC functionality integration tests from `:sql:qa` to a separate
module `:sql:qa:jdbc`. This way the tests are isolated from the rest of the
integration tests and they only depend to the `:sql:jdbc` module, thus
removing the danger of accidentally pulling in some dependency that may
hide bugs.
Moreover this is a preparation for #56722, so that we can run those tests
between different JDBC and ES node versions and ensure forward
compatibility.
Move the rest of existing tests inside a new `:sql:qa:server` project, so that
the `:sql:qa` becomes the parent project for both and one can run all the integration
tests by using this parent project.
To avoid having to specify each spec by hand (which can miss specs to be
added), the test infrastructure now performs classpath discovery so that
each spec added, is automatically considered.
Relates #40358
* Added Limitations page
* Made the aggregations page follow the common template for functions
* Modified all tables to have the first row's cells content centered
* Polishing in other various sections
