Update for the deprecation of BitmapDescriptor.fromBytes

[LuisReyes98]

As of google_maps_flutter_platform_interface: 2.8.0
The method BitmapDescriptor.fromBytes has been deprecated in favor of BitmapDescriptor.bytes and BytesMapBitmap.
The changes in this pull request include

• The changes added in the example and the code focus on updating the package to flutter 3 and above
• Updating the minimum dart SDK to 3.0
• Replacing the use of BitmapDescriptor.bytes to BitmapDescriptor.fromBytes .
• Updating the size of widgets on the example because the BitmapDescriptor.bytes solves a platform specific bug with the marker size , this fix in turn make the markers too big

Consideration for migration added on the README with the following text

Migrating to 1.0

The update to the google_maps_flutter_platform_interface: ^2.8.0 changes that, Deprecate BitmapDescriptor.fromBytes in favor of BitmapDescriptor.bytes and BytesMapBitmap.

Declaring a multiplatform marker

WidgetMarker(
  position: cafePosition,
  markerId: 'cafe',
  widget: Container(
    color: Colors.brown,
    padding: const EdgeInsets.all(2),
    child: Icon(
      Icons.coffee,
      color: Colors.white,
      size: 14 * MarkerGenerator.getDevicePixelRatio(context),
    ),
  ),
)

[LuisReyes98]

@santa112358

[LuisReyes98]

Latest commit also adds all the new props that are available on GoogleMap to be directly available from WidgetMarkerGoogleMap
this props are:

    this.cloudMapId,
    this.webGestureHandling,
    this.style,
    this.clusterManagers = const <ClusterManager>{},
    this.fortyFiveDegreeImageryEnabled = false,
    this.heatmaps = const <Heatmap>{},

[LuisReyes98]

Several updates where made , the suggestion to stop using device pixel ratio was removed do to breaking changes with Safari and web browser compatibility , has been updated to have the most recent google maps support and google_maps_flutter updates

[LuisReyes98]

The README and Changelog has been updated accordingly to explain how to use the new version

[LuisReyes98]

related to this issue #12