All tests that were failing in CI with this diffs showing traces with
context, which correspond to a default `VERBOSITY verbose` in the server.
Since we migrated the CI to postgres 9.6 it makes sense to see such
differences in server configuration.
Enforcing the verbosity level makes the tests more robust indeed.
New functions to perform a precheck for the user data and metadata
parameters that are going to be used to execute a OBS_GetData operation.
Doing this before the OBD_GetData we are able to check if we're going to
have problems with the current request. Is useful because right now
we're using the *_Exception_Safe functions which return NULL in case we
have an exception, this leads to execute the whole request even if we
know beforehand that it's going to fail.
