METADATA: data type for the "EDTF Date" field is EDTF

[shanitajohn]

ACCEPTANCE

• [ ] The date field (:RDF::Vocab::DC11.date) used the ~Europeana~ Extended Date Time Format (EDTF) as it's data type
  • [x] The field should have the label "EDTF Date"

REFERENCE https://docs.google.com/spreadsheets/d/1HZpXyVM8xaZZ9mE2uzsbUmWKbCd6NYJTESOrpQeMa18/edit#gid=0

[mark-dce]

WIP at https://github.com/curationexperts/mahonia/tree/date-edtf

[mark-dce]

ISSUE The EDTF Date field on the show view appears to be showing the value of the Date Label field instead of the EDTF Date. There seems to be similar behavior on the edit form.

ACCEPTANCE

• [ ] The EDTF Date field saves and displays independently of the `Date Label1 field
• [ ] The EDTF Date field appears with proper type information in the Turtle view with the predicate ` http://purl.org/dc/elements/1.1/date
• [ ] The Date Label field appears as a string in the Turtle view with the predicate <http://rs.tdwg.org/dwc/terms/verbatimEventDate>

[mark-dce]

FWIW - it looks like the predicate for EDTF Date was changed incorrectly in this PR https://github.com/curationexperts/mahonia/commit/8598f9ef71bace7275dc66f65c60cba212f7b208. The predicate for the date attribute should have remained DC11.date - it's a separate thing from the label for the date.