[google_maps_flutter_web] Pass BitmapDescriptor.fromBytes size to JS SDK (2/2)

[ditman]

Updates conversion of BitmapDescriptor.fromBytes marker icons to support the new size parameter.

Also:

• Minor refactor to extract the conversion of BitmapDescriptor to gm.Icon to a separate method.
• Updates test mocks to the ones generated by the currently selected version of Mockito (5.3.0)

Issues

• Blocked by [google_maps_flutter_platform_interface] Adds size to BitmapDescriptor (1/2) #6208 (also contained here, this needs to be rebased once 6208 lands)
• Fixes google_maps_flutter_web marker too big flutter#73789

Tests

• Added browser test for this new parameter
• Deployed repro-app here: https://dit-maps-tests.web.app

Needs one final rebase

• This will fail several checks (publishable at least?) until the platform_interface PR listed above lands. Feel free to skip the code in the platform_interface package from this PR.

Pre-launch Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• I read the Tree Hygiene wiki page, which explains my responsibilities.
• I read and followed the relevant style guides and ran the auto-formatter. (Unlike the flutter/flutter repo, the flutter/plugins repo does use dart format.)
• I signed the CLA.
• The title of the PR starts with the name of the plugin surrounded by square brackets, e.g. [shared_preferences]
• I listed at least one issue that this PR fixes in the description above.
• I updated pubspec.yaml with an appropriate new version according to the pub versioning philosophy, or this PR is exempt from version changes.
• I updated CHANGELOG.md to add a description of the change, following repository CHANGELOG style.
• I updated/added relevant documentation (doc comments with ///).
• I added new tests to check the change I am making, or this PR is test-exempt.
• All existing and new tests are passing.

If you need help, consider asking for advice on the #hackers-new channel on Discord.

[stuartmorgan-g]

LGTM

[ditman]

Thanks for taking care of this one @stuartmorgan, I've added the autosubmit label so it lands whenever. 🙏