Add /usr/local/bin executable

[sbesson]

Fixes #59

Adds a task creating an /usr/local/bin/omero executable (symlinking to /opt/omero/server/OMERO.server/bin/omero) and update the Molecule tests to use this executable.

For bash environment, this means that on an OMERO.server system provisioned by Ansible, the following commands should just work out of the box for any user (i.e. without the path prefixing)

omero login
omero import

[joshmoore]

Technically, makes sense. I think the only reason this wasn't done previously was that there would be a disconnect between an ansible install and a non-ansible install. Personally, I think that's covered now by the need to either activate the virtualenv or the conda environment.

[sbesson]

Thanks @joshmoore. The former rationale and the intent to control the divergence between both scenarios makes complete sense. In that case, since the /opt/omero/server/OMERO.server/bin/omero wrapper script is already Ansible-specific, I don't think we are increasing it much further.

From my side, there is no urgent timeline for this to be tagged apart from the original issue. My only consideration is that the IDR submission workflow might benefit from this simplification as it removes the need for the /opt/omero/server/OMERO.server/bin prefix for every CLI command. So a proposal would be to get this in a patch release and deploy it into a pilot server for assessment./cc @pwalczysko @dominikl @will-moore