[Fixes #118] Port rndt to GeoNode 5

[etj]

Replaced by #121 since this one incorrectly targets 4.4.x

This PR contains cumulative commits to be squashed for the alignment of this app to GeoNode5 (#118 )

First commit features a working metdata editor.
It removes all the pre-5 geonode hooks, templates, etc, and implements:

• Json schema and handler
• Labels for metadata fields
• Thesauri renamed to improve automatic loading
• Template ISO19115
  • Includes templatetags cleanup

Still missing:

• storer (needs Review parser/storer design GeoNode/geonode#12902)
• facets
• database migrations
• model cleanup (LayerRNDT is no longer needed)

[etj]

Testing required

env preparation

In settings, add the RNDT app and set the metadata template:

INSTALLED_APPS += ("rndt",)
GEONODE_APPS += ("rndt",)

CATALOG_METADATA_TEMPLATE = "xml/template-rndt.xml"

You should also add (manually, at the moment), the thesauri at https://github.com/geosolutions-it/geonode-rndt/tree/118_port_to_geonode5/thesauri

admin

You should create (at least) 3 group profiles.

Then, in the RNDT admin tab, create 2 public administrations, annotating their IPA. The IPA is the code that will be prefixed into the resource's UUID in order to find out to which PA the resource belongs to.

In the RNDT tab you can also associate PA to group profiles using the "Group Profile RNDT" entries. Associate 2 of the group profiles to the 2 created PAs.

test cases

Create a layer, and edit its metadata.

Test: Metadata customization

Metadata should have:

• a dropdown for access constraints
• either a dropdown for use constraints, or a freetext; the options should be selectable
• accuracy field
• distance field

Test: IPA prefixed UUID

The UUID of a resource should be prefixed with the IPA code of the associated group, in the format "IPA:UUID"

• Associate a group linked to a PA to the resource --> The related iPA should be present in the fileIdentifier (uuid)
• Change the associated group, with another associated to a different PA --> the UUID should contain the new IPA
• Change the associated group, with another NOT associated to a PA --> the UUID should not contain any prefixed IPA

Test: import / export metadata

• the exported metadata should be in RNDT compliant format
  • the metadata standard name and metadata standard version should report info about the RNDT version
  • there should be present all the aforementioned custom fields (accuracy, resolution), and the LegalConstraint should report INSPIRE related Anchors
• when importing xml metadata, all the aforementioned custom fields should be parsed and imported

Test: migration

Data from a GeoNode4/RNDT instance should be imported and migrated. This test can be postponed to the first real migration.

[Gpetrak]

As a reminder note: this PR can be closed because of this: #121 which includes the master as target instead of 4.4.x