It turns out that when passing the raw sql as form data the newlines
were being lost, this ensures that they are preserved by passing a
json blob instead.

This also includes a new 'implicit_db' to the list of detected
databases as it can be that a query is using it.

Signed-off-by: David Caro <david@dcaro.es>

Modified the tests to send the params as json.
Added the tests for the use cases for implicit db detection.
Ran locally with curl to see the error when the wrong headers are passed, and
the success when the good ones.