Improve error messages by returning the original SQL statement
declaration instead of trying to reproduce it as the casing and
whitespaces are not preserved accurately leading to small
differences.
Close#37161
Added warnings checks to existing tests
Added “defaultTypeIfNull” to DocWriteRequest interface so that Bulk requests can override a null choice of document type with any global custom choice.
Related to #35190
Moves `x-pack/qa/sql/*` into `x-pack/plugin/sql/qa` to make it simpler
to run all of the sql tests. This lines up with how newer projects like
cross cluster replication are testing themselves.