[google_maps_flutter] add support for projection toScreenLocation() and fromScreenLocation()

[victorbucutea]

…ScreenLocation()

Description

support for projection toScreenLocation() and fromScreenLocation() + example ui

Related Issues

flutter/flutter#24213.

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[victorbucutea]

@googlebot I signed it!

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[otopba]

@victorbucutea
Hi! Could you merge original master to this PR ? Thank you

[sanekyy]

@victorbucutea
Hello. You use wrong code style for this project.

You can setup correct code style with google java format plugin.

After this verify changes with flutter_plugin_tools and fix all warnings and errors, please.

You can read about how to do it in contribution guide.

Thank you in advance.

[stuartmorgan-g]

Thanks for the contribution. However, it appears that this was obsoleted by #2108, so closing.