Showing more information and options when adding WMS layers

[kazemar]

When entering a WMS query, the list of the available layer appears below.

1. By adding a new remote layer, we could have more details if they were listed in a table.
   We already show TITLE and NAME, and can add the ABSTRACT field.

2. Otherwise, using a checkbox would avoid the manipulations when adding multiple layers from the same WMS.

3. Adding an information to let know if a layer is already loaded would also minimize the back and forth when looking or testing layers

4. Ordering the layers
   If you take the example of this WMS : https://www.georisques.gouv.fr/services?service=wms&request=getcapabilities
   The layers are categorized :

<layer><Name>PPRN_COMMUNE_GASPAR</Name>
    <layer queryable="1"><Name>PPRN_COMMUNE_AVALANCHE_APPROUV</Name></layer>
    <layer queryable="1"><Name>PPRN_COMMUNE_AVALANCHE_PRESCRIT</Name></layer>
    etc.
</layer>
<layer><Name>PPRT_COMMUNE_GASPAR</Name>
    <layer queryable="1"><Name>PPRT_COMMUNE_RISQIND_APPROUV</Name></layer>
    <layer queryable="1"><Name>PPRN_INOND_FXX</Name>
</layer>
<layer><Name>DI_COVADIS</Name>
    <layer queryable="1"><Name>TRI_COMMUNE</Name></layer>
    <layer queryable="1"><Name>ENJEUX_RESEAUX</Name></layer>
</layer>

-> The category layers (ex: "PPRN_COMMUNE_GASPAR") have only a tag
-> The content layers (ex: "PPRN_COMMUNE_AVALANCHE_APPROUV") have a <layer queryable="1" [or "0"]> tag

This could help to make an automatized sorting of the datas, and to give the possibility for a GetFeatureInfo tool.

It could look like this :

<checkbox (checked and unchangeable if loaded)> TITLE 1 (category) | TITLE 2 (thematic) | NAME | ABSTRACT