Feature Request: reactive layers

[jasonhibbs]

I love where this module is going, so here’s my request for the soal-mapbox feature I use the most.

For paint, layout, and filter, soal-mapbox used watchers to update the map. Here’s an example:

    if (this.layer.paint) {
      this.$watch(
        "layer.paint",
        function(next) {
          if (this.initial) return;
          if (next) {
            for (let prop of Object.keys(next)) {
              this.map.setPaintProperty(this.layerId, prop, next[prop]);
            }
          }
        },
        { deep: true }
      );
    }

[AlexLavoie42]

Totally missed watching the layer properties. I am doing this for most other components.

Would be pretty easy to just copy what is used in MapboxMap.vue over to the layer component for properties that can be modified.

PR would be greatly appreciated if possible!