Attribute table - Add support to use WFS search parameters

[maan002]

Is your feature request related to a problem? Please describe.
The Attribute table feature now expects that there is a WFS service with almost the same URL as the WMS.

For a layer 'Parkering' with a WMS URL:
https://service.sydnarke.se/geoserver/pub_klek_tek_gata_pa_v1/wms
the Attribute table code expects a WFS URL at:
https://service.sydnarke.se/geoserver/pub_klek_tek_gata_pa_v1/wfs

This isn't always the case

Describe the solution you'd like
I suggest that the code is updated to use the WFS search parameters that one can specify for a WMS layer.

Fall back to the old logic if these parameters are not specified.