Improve nuxeo-tags to infer the items' type

Currently, nuxeo-tags receives a list of items and a type, which can be user, group or tag. Type tag fallsback on nuxeo-tag whereas user and group rely on nuxeo-user-tag and nuxeo-group-tag respectively. However, since the items can be resolved object with, we should improve nuxeo-tags so that the if no type is defined, the type should be inferred from the object's entity-type.
We should then make this the default usage of this element, where type should only be defined when passing a list of ids (and not objects) as items. We should clean up it's usage on Web UI and addons.