PR #3747 stopped ignoring Podfiles and added the missing iOS Podfiles,
but not the macOS Podfiles.

- Rename incremental_build.sh to tool_runner.sh since it has been used for things other than building for a while, and also isn't always incremental.
- Replace check_publish.sh with tool_runner.sh to reduce the number of special-case scripts. This is a small behavioral change in that now PRs that don't change any packages will test all packages, as with our other scripts.
- Eliminate check_changed_packages. All critical uses have now been replaced by the Dart version of the logic, and the one remaining use was purely for an error message that says something that should be relatively easy to figure out from context anyway.

This means we have less bash code to maintain (without unit tests) and understand.

Many of our integration tests weren't actually being run on CI because they were in the wrong place and/or missing the driver file, and it seems we've just never noticed. This makes a number of changes:
- Ensures that all packages with integration tests also have a driver file in the right location.
  - Also standardizes the format of those files, as the boilerplate `main()` is available in `integration_test`.
- Ensures that all integration_test directories are in the right place.
  - In a couple of places, removes a duplicate copy of the integration test file.
- Makes it an error for a plugin that's not excluded to not have integration tests, so this can't easily happen again.
- Adds logging of what's being run and skipped, so if something does go wrong in the future it's easy to determine what from the logs.
  - Excludes `*_platform_interface` since the logging was (potentially confusingly) reporting that they were skipped because they don't support the current platform. Skipping them is correct, just not for that reason.
- Excludes the plugins that currently have no integration tests, with references to issues about adding them.

Fixes flutter/flutter#81929

ios_platform_images does not currently have an integration test, and file_chooser does not have a web integration test, so both must be explicitly excluded due to recent tooling changes.

See:
flutter/flutter#82208
flutter/flutter#82211

Fixes flutter/flutter#81847

Adds some improvements to the platform interface. 

1. Make `InAppPurchasePlatformAddition` a subclass of `PlatformInterface` to take advantage of the existing token checking logic. (I also consider `InAppPurchasePlatformAddition` a `PlatformInterface` because it works in a similar way.
2. Make the `instance` variable `late` as we should never access it before setter.
3. Add tests for `InAppPurchasePlatformAddition`

part of flutter/flutter#78525

…ation (#3851)

)

* Expose in_app_purchase_exception.dart correctly

* Update iOS implementation to use new instance

…lient library. (#3845)

* Implement BillingClientWrapper and unit-tests

* Android specific implementation

* Moved Android specific methods into addition class

* Added missing line end

* Purchases status to restored after call restorePurchases

* Don't force GooglePlayPurchaseParam

* Implement registerPlatform method

* Added TODO comment to add example

* Fixed mistake in API documentation

* Added additional assert to test enablePendingPurchase

* Update Android implementation with latest platform_interface

Fixes flutter/flutter#81848

Also fixed some headers in the readme and one more link

Prepare for v5.0.3 release

)


Add a PubVersionFinder class to easily fetch the version from pub.

Add an against-pub flag to check-version command, which allows it to check the version against pub server

Make the 'publish-check' command to check against pub to determine if the specific versions of packages need to be published.
Add a log-status flag, which allows the publish-check command to log the final status of the result. This helps other ci tools to easily grab the results and use it to determine what to do next. See option 3 in flutter/flutter#81444

This PR also fixes some tests.

partially flutter/flutter#81444