XMP PLUS LicensorTelephoneType1,2 values are printed not translated

[sarunasb]

Describe the bug

LicensorTelephoneType1,2 values are defined in controlled vocabulary, but are printed as underlying URL, not interpreted.

To Reproduce

Using reference images from https://iptc.org/std/photometadata/examples/.

$ /usr/bin/exiv2 -px -gplus IPTC-PhotometadataRef-Std2023.2.jpg
… … …
Xmp.plus.Licensor[1]/plus:LicensorTelephoneType1 XmpText    36  http://ns.useplus.org/ldf/vocab/work
Xmp.plus.Licensor[1]/plus:LicensorTelephoneType2 XmpText    36  http://ns.useplus.org/ldf/vocab/cell
… … …
Xmp.plus.Licensor[2]/plus:LicensorTelephoneType1 XmpText    36  http://ns.useplus.org/ldf/vocab/work
Xmp.plus.Licensor[2]/plus:LicensorTelephoneType2 XmpText    36  http://ns.useplus.org/ldf/vocab/cell
… … …

Expected behavior
Printed should be values interpreted according to TagVocabulary defined in src/properties.cpp:

//! XMP plus:LicensorTelephoneType
constexpr TagVocabulary plusLicensorTelephoneType[] = {
    {"cell", N_("Cell")}, {"fax", N_("FAX")}, {"home", N_("Home")}, {"pager", N_("Pager")}, {"work", N_("Work")},
};

…that is, something like this:

Xmp.plus.Licensor[1]/plus:LicensorTelephoneType1 XmpText    36  Work
Xmp.plus.Licensor[1]/plus:LicensorTelephoneType2 XmpText    36  Cell

Desktop (please complete the following information):

• Linux Debian Unstable
• exiv2 0.28.5 from Debian repository

Additional context

LicensorTelephoneType1,2 fields are the only XML PLUS fields, which:

• are subfields of parent structure (Xmp.plus.Licensor) and
• are of URL type and
• use controlled vocabulary for possible tag values.

The rest of XMP PLUS URL-type controlled dict. fields have their values printed translated correctly.