Add the ability to show/hide vector feature layers directly from the legend

[shirlysteph]

Description: Add an icon of some sort that will allow the user to toggle layer visibility directly from the Legend Panel instead of doing it through the Filter by Property view. In a sense do what Filter by Property does, but as a short-cut. May need to do some mock-ups to determine the best way to do this without overcrowding the Legend Panel.

Context: This is a feature addition to the "Filter by Property" feature (see issue #1770) and extension of issue #2713. The filter feature currently allows the user to toggle the visibility of vector features on the map based on filterable properties. For example, the Permafrost Zones layer can be filtered and their visibility adjusted based on various zone types. The values for some of these properties (e.g., zone types) are configured in the legend using the color palette set in the portal configuration document. The current request is to toggle visibility of layers from within the legend panel.