Update Leaflet to 1.7.1 and make the map global accessible

[Falke-Design]

Hi,

I'm coming from SO because of this post. While I digging into the problem, I saw that your plugin uses a very old version of Leaflet. The newest release is 1.7.1 and you are using 0.7.3 from the year 2013.
I recommand to update Leaflet there are many issues fixed since them and compatibility for mobile divces is now much better.

Also I suggest to add an option, so that the developer can decide if the map variable of the script leaflet-filters is added to the window object (which makes it global accessible). This would make it possible that the user can add own Leaflet layers / logic to the map.

The following line after this.map=L.map(this.params["map-container"],options); would be enough:

window.map = this.map;

locateandfilter/public/js/leaflet-filters/leaflet-filters.js

Lines 255 to 265 in beeca2c

	this.createMap=function() {
	var self=this;
	var options={
	"center": new L.latLng(this.params["initial-lat"],this.params["initial-lon"]),
	"maxZoom":this.params["overlay"]["maxZoom"],
	"minZoom":this.params["overlay"]["minZoom"],
	"scrollWheelZoom":this.params["scrollWheelZoom"],
	"worldCopyJump" : true
	};
	this.map=L.map(this.params["map-container"],options);