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
Extend SHOW TABLES, DESCRIBE and SHOW COLUMNS to support table
identifiers not just SQL LIKE pattern.
This allows both Elasticsearch-style multi-index patterns and SQL LIKE.
To disambiguate between the two (as the " vs ' can be easy to miss),
the grammar now requires LIKE keyword as a prefix for all LIKE-like
patterns.
Also added some docs comparing the two types of patterns.
Fix#33294
