[google_maps_flutter_web] Implements updateTileOverlays

[ShahinTaj01]

Adds implementation for updateTileOverlay in google_maps_flutter_web to prevent UnimplementedException.
This PR Fixes Issue: flutter/flutter#76361

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[ShahinTaj01]

@googlebot I signed it!

[ShahinTaj01]

@ditman Could you help review this ?

[ditman]

This is looking great! Thanks for the contribution!

As discussed in the original issue, please also implement the clearTileCache method as an empty method? That way all the "Tiles"-related functionality won't crash in web.

As a quick review; there's a checklist when you create a new PR with a bunch of things that need to be done before the PR can be merged. I'm going to list the missing stuff so we can merge this:

1. Add a test here so we can verify that calling the methods you added don't throw exceptions anymore (a completion test of the returned value is more than enough).
2. Update pubspec.yaml (with a bump to the patch version number, so everybody picks up this change automatically)
3. Update CHANGELOG.md with a brief description of the changes.

Thanks!

[ditman]

I'm merging this into: #3673

Thanks for the contribution @ShahinTaj01!

[ditman]

Published here https://pub.dev/packages/google_maps_flutter_web/versions/0.2.0