Enhancement: URLParams props for ReactiveMap component

**Issue Type:**

enhancement

**Platform:**

Web for Maps

**Description:**

We currently don't have a way to store the state of the map (i.e. the current center location, zoom level). This prevents capturing the accurate search state with maps.

We can use the `URLParams` prop with the ReactiveMap component (similar to how we have for ReactiveSearch components) that when set will generate a querystring param for the map's current center location and zoom level. If these params are present when opening a ReactiveSearch state, the map component will initialize the `defaultCenter` and `defaultZoom` props using these values.

**Reactivesearch version:** x.y.z

@appbaseio/reactivemaps: 2.0.0-beta-02