Add token to ArcGIS catalog members

[nf-s]

Add token to ArcGIS catalog members

Some ArcGIS catalog items/groups didn't have a token trait - so I've added one. This allows users to use API-key based authentication.

Changes:

• Add token to ArcGisMapServerCatalogItem, ArcGisMapServerCatalogGroup, ArcGisFeatureServerCatalogItem, ArcGisFeatureServerCatalogGroup, ArcGisImageServerCatalogItem and ArcGisCatalogGroup - if defined, it will be added to the token parameter for all ArcGIS Rest API requests.
  • Added tokenUrl to ArcGisImageServerCatalogItem, and tweaked behaviour in ArcGisMapServerCatalogItem and ArcGisImageServerCatalogItem so that if both token and tokenUrl are defined, then tokenUrl will be used. This allows the token to be refreshed if needed.

Checklist

• There are unit tests to verify my changes are correct or unit tests aren't applicable (if so, write quick reason why unit tests don't exist)
• I've updated relevant documentation in doc/.
• I've updated CHANGES.md with what I changed.
• I've provided instructions in the PR description on how to test this PR.