Checks WMS/WFS for each fields in the CFG when saving

[Gustry]

When saving the CFG, we need to check for each tool if the field is published for WFS :

• [ ] Locate by layer:

  • [x] display field - WFS needed
  • [x] optional groupby - WFS needed
  • [ ] display the geometry : qgis server needed

• [x] Attribute table:

  • [x] primary key : WFS needed
  • fields to hide, no need to check for WFS

• [ ] Layer editing :

  • [x] snap layers must be WFS enabled (done in 04504216d6b4c9a000377037455ceeeae2310724)

• [ ] Tooltip layers:

  • [x] list of fields separated by comma WFS needed
  • [ ] display geom : needs qgis server checkbox

• [x] Dataviz :

  • [x] X field : WFS needed
  • [x] Y field in each trace : WFS needed
  • [x] Z field
  • [x] Color field

• [x] time manger

  • [x] start field : WFS enabled
  • [x] end field : WFS enabled

• [ ] Atlas :

  • [x] primary key : WFS enabled
  • [x] feature label : WFS enabled
  • [x] sort field : WFS enabled
  • [ ] highlight geom : qgis server checkbox

Not concerned :

• Filter by attribute
• Filter by polygon
• Attribute table → Hidden fields...
• Form filter

CC @mdouchin @rldhont if I made any mistake