For code review

Added status messages for queries in progress.

Moved the query caching code underneath the result publish code, as the
caching was increasing the time before the result was returned.

Also added the Minio environment variables to the Kubernetes deployment.

Re-ordered operations in the method as well. Empty database check now
happens before query translation.

Result message now also uses the entity.MessageStruct. This will have to
be changed in the frontend before merging.

Replaced all maps in the handleMessage method with the MessageStruct,
except for the final result, as this one uses the key 'values', where
the rest use the key 'value'. Once this has been changed in the frontend
it will be updated in the backend as well.

Fix :)

Everything in order, gl front end :) @Joris + @Lorenzo

If there is an error retrieving the database info an error is now
returned.

Most of this code was taken straight from the schema service. No tests
were written because this is entirely dependent on external
dependencies.

An error message now gets published if there is an error while
converting the query or there is a database error.

Updated integration test

Also updated Makefile and deployment file.