In facility data, update OAI-PMH's link semantics to be the OAI-PMH endpoint

In OAI-PMH, the request (the "verb") is embedded in the URL by appending ?verb=REQUEST; e.g., the Identify request results in ?verb=Identify being appended. In other words, to make an Identify request to the OAI-PMH endpoint https://oai-pmh.example.org/request, the HTTP client makes a GET request that targets the https://oai-pmh.example.org/request?verb=Identify.

The facility-specific data (_data/facilities.yml) optionally records an OAI-PMH endpoint for each facility; for example,

  odr:
    link: https://data.esrf.fr/
    oai-pmh-endpoint: 
      link: https://icatplus.esrf.fr/oaipmh/request?verb=Identify
      last-check: 2024-02-07
      status: Active

Note that the link field stores the URL of the Identify request, rather than the actual OAI-PMH endpoint. This URL is used by the verification script (scripts/check_oai_pmh.rb) to check the current status of the endpoint.

The link values and the verification script should be updated so the _data/facilities.yml file stores the OAI-PMH endpoint in the link field, with the script adding the ?verb=Identify suffix, following the OAI-PMH specification.