[google_maps_flutter] Add marker clustering support - iOS implementation

[jokerttu]

This PR introduces support for marker clustering for iOS platform

An example usabe is available in the example application at ./packages/google_maps_flutter/google_maps_flutter_ios/example/ios12 on the page Manage clustering

This is prequel PR for: #4319
and sequel PR for: #6158

Containing only changes to google_maps_flutter_ios package.

Follow up PR will hold the app-facing plugin implementation.

Linked issue: flutter/flutter#26863

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/packages repo does use dart format.)
• I signed the CLA.
• The title of the PR starts with the name of the package surrounded by square brackets, e.g. [shared_preferences]
• I linked to 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.

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[hellohuanlin]

The code looks quite clean. But I feel I don't know enough about clusters to stamp it just yet. Could you also invite the reviewers from your previous PR?

[hellohuanlin]

can you add some unit tests on native side?

[jokerttu]

@hellohuanlin

can you add some unit tests on native side?

Added some native unit tests

[hellohuanlin]

Thanks for adding those tests. The overall code looks clean.

@cbracken feel free to give it another pass (if you see fit) since you are the new owner. Otherwise I think it's good to land.

[stuartmorgan]

This day has come :) We now require iOS 14+.

[jokerttu]

Updating Google-Maps-iOS-Utils library seems to cause problems.

https://github.com/googlemaps/google-maps-ios-utils/blob/0e7ed81f1bbd9d29e4529c40ae39b0791b0a0eb8/Google-Maps-iOS-Utils.podspec#L24

Output after updating the version:

[!] CocoaPods could not find compatible versions for pod "GoogleMaps":
  In Podfile:
    google_maps_flutter_ios (from `.symlinks/plugins/google_maps_flutter_ios/ios`) was resolved to 0.0.1, which depends on
      Google-Maps-iOS-Utils (= 4.2.2) was resolved to 4.2.2, which depends on
        GoogleMaps (~> 7.3)

    google_maps_flutter_ios (from `.symlinks/plugins/google_maps_flutter_ios/ios`) was resolved to 0.0.1, which depends on
      GoogleMaps (< 9.0, >= 8.4)

Version 4.1.0 does not work anymore either:
Throwing "User-Defined Issue (Xcode): Unsupported Swift architecture" issue on build phase

[stuartmorgan]

Sounds like this is blocked on googlemaps/google-maps-ios-utils#456 then.

I would image that will be fixed soon, because Google Maps 7.3 isn't compliant with the upcoming App Store privacy requirements, so the current version of Google-Maps-iOS-Utils will become essentially unshippable once enforcement of those requirements starts.

[jmagman]

@jokerttu is this ready for re-review?

[jokerttu]

@jokerttu is this ready for re-review?

@jmagman not yet, this is waiting new release of Google-Maps-iOS-Utils library to have support latest Google Maps SDK versions. See discussion here: #6186 (comment)

[stuartmorgan]

FYI I have raised the blocking issue internally with the Google Maps team.