From metasearch search results enable add OGCAPI Features service to map

[pvgenuchten]

Feature description.
When a metasearch search result (a metadata record) contains a link to a OGCAPI-Features service, the add-service-to-map button should enable and when clicked, open the add-wfs-panel with the service url pre selected.

Additional context
QGIS does support loading of a OGCAPI Features service (as part of the add-wfs panel).
Interesting aspect here is: how do you detect that the link involves a ogcapi-features service?
A PR is being prepared to add ogcapi-features to the list of known protocols to be included in metadata links to identify different types of services. An alternative approach is to parse the url to identify if an open-api-endpoint is available at {url}/openapi.
Note that the metadata link may link to the service, in which case the user still has to select the relevant collection to add, or to the actual collection {url}/collections/{collection}, in which case the relevant collection can be preselected on the add-service panel.

[pvgenuchten]

Work on the plugin is progressing well, some ideas for improvement before actual PR:

• do not ask to overwrite metasearch connection when adding wms, instead: add checkbox, remember choice. or look in list of available connection to see if one of them has same url.
• open gis file, if type is zip, unpack the zipfile before loading. if type is folder-of-files, html or unknown, show as link to download the file manually
• allow to use main ogc api endpoint, show a dropdown to select a record-collection
• a configuration switch on owslib to use the qgis request library, so all requests by owslib are logged in qgis logger (and qgis proxy configuration is auto-included)
• some metadata records list as part of the connection details the layername, metasearch can then skip the 'select layer' panel and directly add the layer
• add option to open ogcapi-features, ogcapi-maps, ogcapi-coverages links from metadata