Add definition for isoparatype.

[MattBlissett]

Update: just add isoparatype, and await advice from a taxonomic expert for the rest (see #60).

Two type status terms (hypotype, plesiotype) are present in the GBIF API, but not in the vocabulary. They were added to the API after this discussion.

Another term, isoparatype, is requested to be added by ALA.

This PR will add the three a single terms with these definitions:

Hypotype: A specimen that was not part of the original type series of the species, but is known from a published description, figure, or listing. [Zoo.]

Isoparatype: A duplicate of a paratype, compare paratype. [Bot.]

Plesiotype: A specimen upon which a subsequent or additional description or illustration of a previously named species is based. [Zoo.]

See also CatalogueOfLife/backend#949 . I'll wait for advice from the Catalogue of Life taxonomy group (or other appropriate experts) before merging this; it's difficult to find good definitions for these terms.

https://species-id.net/zooterms/hypotype, https://species-id.net/zooterms/plesiotype and http://www.insdc.org/controlled-vocabulary-typematerial-qualifer are the sources.

[MattBlissett]

diff vocabulary/gbif/type_status.xml vocabulary/gbif/type_status_2021-01-18.xml --ignore-all-space
5c5
<       dc:description="A vocabulary to be used for a nomenclatural type status of a specimen or name. See also the related type reason vocabulary."
---
>       dc:description="A vocabulary to be used for a nomenclatural type status of a specimen or name. See also the related type reason vocabulary. This release adds isoparatype."
7c7
<   dc:issued="2015-02-13"
---
>   dc:issued="2021-01-18"
208a209,219
>  <concept dc:identifier="isoparatype" dc:URI="http://rs.gbif.org/vocabulary/gbif/type_status/isoparatype"
>   dc:relation="http://rs.gbif.org/vocabulary/gbif/type_status/isoparatype"
>   dc:description="A duplicate of a paratype, compare paratype. [Bot.]">
>   <preferred>
>    <term dc:title="isoparatype" xml:lang="en"/>
>   </preferred>
>   <alternative>
>
>   </alternative>
>  </concept>
>