Support passing custom gesture recognizers to AdWidget

[PaananenReko]

Description

This pull request lets developers pass their own gesture recognizers to AdWidget on both Android and iOS. By providing a gestureRecognizers parameter, you can ensure that user interactions—such as swipes, taps, or pans—behave as intended and blend smoothly with your app’s UI.

Changes:

• Adds a gestureRecognizers parameter to AdWidget.
• Integrates these recognizers into underlying platform views for Android and iOS.
• Includes an iOS test confirming that custom recognizers are passed correctly. (Android testing was not reliable due to current test environment constraints.)

Why This Matters: Without custom recognizers, certain gestures may not register properly, potentially clashing with your app’s existing UI elements. With them, you can achieve more intuitive and responsive ad interactions.

Demos: Videos included show the difference in user experience with and without custom gesture recognizers.

default.mov

with_gesture_detectors.mov

Checklist

• I read the Contributor Guide and followed the process outlined there for submitting PRs.
• My PR includes unit or integration tests for all changed/updated/fixed behaviors (See Contributor Guide).
• All existing and new tests are passing.
• I updated/added relevant documentation (doc comments with ///).
• The analyzer (flutter analyze) does not report any problems on my PR.
• I read and followed the Flutter Style Guide.
• I signed the CLA.
• I am willing to follow-up on review comments in a timely manner.

Breaking Change

Does your PR require plugin users to manually update their apps to accommodate your change?

• Yes, this is a breaking change (please indicate a breaking change in CHANGELOG.md and increment major revision).
• No, this is not a breaking change.