Add a list of well-known vocabularies to "Add model" button

[jakubklimek]

When adding new external vocabulary through:

It could be a quick win to add a few buttons pre-filling well-known vocabulary IRIs (with CORS support) at least for the demo in this dialog:

I suggest to add these (used in the demo):

• RDF
• RDFS
• Dublin Core Terms
• FOAF
• SKOS

Alternatively, they could be added directly next to the "model" button in CME, since we have "sgov" there.

[jakubklimek]

The tab names now do not fit the contents - the first two seem to be switched:

In addition, I would change the terminology a bit:

• "model" => "vocabulary" (model is an internal term)
• "select model to import" => "well-known vocabularies"
• "Import from URL" => Vocabulary from URL
• "Create a new local model" => "Crate new vocabulary"

etc.

[jakubklimek]

Just a minor: vocabularies