Override `process()` in `BinaryLogicProcessor` which doesn't immediately
return null if left or right argument is null, which is the behaviour of
`process()` of the parent class `BinaryProcessor`.
Also, add more tests for `AND` and `OR` in SELECT clause with literal.
Fixes: #35240
Add NotEquals node in parser to simplify expressions so that <value1> != <value2> is
no longer translated internally to NOT(<value1> = <value2>)
Closes: #35210Fixes: #35233
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.
Andrei Stefan
Marios Trivyzas
Costin Leau
Nik Everett