REST calls to the org.eclipse.vorto.repository.web.core.ModelSearchController can be replaced by direct calls to the API search controller

[ghost]

Following the search improvement task and the removal of one endpoint in the specific search controller in package org.eclipse.vorto.repository.web.core, it would be coherent to remove the other endpoint as well ("/public"), and thus the whole controller could be obsoleted.

The front-end issuing REST calls to it ("tenantManagement.js" in the "repository-web" module) could directly call the search with "./api/v1/search/models?expression=visibility:Public".

@aedelmann the one thing I am not able to figure out at this time, is how exactly this endpoint is used at all. The angular controller is referenced in the "admin-template.html" resource, but contrary to its sibling functionality I replaced, I cannot trigger the REST call at all.
The javadoc in ModelSearchController does not help, since it only seems to refer to the namespace functionality.
Any thoughts?

[ghost]

Pull request here.
As mentioned above, I could not find an actual case where this was used, so I am (maybe blindly) assuming that this was, in fact, not used at all.
@aedelmann if you know for a fact I am wrong on this assumption, please let me know so I can test the change practically (it is a trivial change, but a little testing wouldn't hurt).