adding support for ios custom action overrides when switch control is enabled

[chunhtai]

Description

The framework counter part flutter/flutter#82746

The custom action overrides will now be support in ios in favor of adding fake switch control. There is currently no available api to turn on native switch control(scrolling for example) for UIView. We have to workaround it by adding custom actions to imitate those native switch control. This pr makes accessibility bridge in ios to accept custom action overrides for existing semantics action. If it receive such overrides, it will add the imitating custom action into all of its children but itself.

Related Issues

flutter/flutter#37974

Tests

I added the following tests:

see files

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Breaking Change

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[chinmaygarde]

cc @goderbauer Do you have additional context on how to review and land this? The linked framework PR seems to be open still. If, OTOH, this PR is stale, can we close it for now?

[chunhtai]

close until i have time to get back to this pr

[chunhtai]

waiting for review

[chunhtai]

superseded by #26671