HPCC-9411 Information needed about unloadable roxie queries

Queries that cannot be loaded for some reason will now be created as dummy
query entries, so that they will still appear in the output from
control:queries.

Signed-off-by: Richard Chapman <rchapman@hpccsystems.com>
Merge pull request #4445 from richardkchapman/roxie-bad-query

HPCC-9411 Information needed about unloadable roxie queries

Reviewed-by: Gavin Halliday <ghalliday@hpccsystems.com>