* @description Adds the draw control to the map provided. Creates an on-draw and on-click event that allows users to draw polygons onto the leaflet map.
* @function AstroDrawControl.prototype.onAdd
* @description Adds the draw control to the map provided. Creates an on-draw and on-click event
* that allows users to draw polygons onto the leaflet map.
* @param {AstroMap} map - The AstroMap to add the control to.
* @return {Object} The div-container the control is in.
* @description Is called when a user draws a shape using the on map drawing features. Converts the shaped drawn into a Well-Known text string and inserts it into the Well-Known text box.
* @description Is called when a user clicks the draw button below the AstroMap. Will take the Well-Known text string and draw the shape onto the map. If the Well-Known text string is invalid an error will show in the text box.