Changed Legend Functionality

[snowcov]

• Improved setMapOnAll function (Primary function for legend)
• Deleted selectState function due to redundancy
• Added Batch system approach to setMapOnAll to simplify adding markers
• Created new helper function for selectAll() function
• Added map data structure to make visibility logic simpler

[Pham-Vincent]

Is it also Possible to have it so when you click the Select all For Usetype it doesn't interact with the States? and Vice Versa?