Add new entity "Project"

[Palollo]

This new entity can be considered at the level of "Datasets" and "Models", so new link "Projects" can be put in the main menu bar.
When the user clicks on that new menu item, the list of project would appear with the contents returned by
GET /projects?purpose=projectList

When the user clicks on any item of the list, then the details of the project would appear with the contents returned by
GET /projects/{code}
A link can be added at the end of this page with the text "Datasets of the project" going to the list of the datasets with the filter for the project, e.g. "https://chaimeleon-eu.i3m.upv.es/dataset-service/datasets?invalidated=false&project=CHAIMELEON".

Of course the properties of the project can be changed by some users as indicated in the property "editablePropertiesByTheUser" (similarly to dataset entity) and there is the operation PATCH to make the changes.

Finally the project has some configuration parameters which can be viewed with
GET /projects/{code}/config
and they can be changed with
PUT /projects/{code}/config
That config params may be viewed and changed by the user if the item config appears in the property allowedActionsForTheUser (similarly to dataset entity), in the object returned by GET /projects/{code} (previously seen as provides the content for the project details page).