feat: Alert handler should support a Promise

[sean-perkins]

Prerequisites

• I have read the Contributing Guidelines.
• I agree to follow the Code of Conduct.
• I have searched for existing issues that already include this feature request, without success.

Describe the Feature Request

Many of the existing overlays already support a Promise to be used with the handler to control when the overlay dismisses. This is not available to ion-alert.

This feature request is to add support to ion-alert to allow for a promise.

Describe the Use Case

Performing an action in the handler callback that requires asynchronous behavior (performing an API call, waiting for user input, waiting a set duration).

Describe Preferred Solution

handler: async() => {
  const res = await this.someService.method(); // res returns `true` or `false` controlling if the alert dismisses 
  return res;
}

Describe Alternatives

No response

Related Code

No response

Additional Information

Split from PR #22518

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Thank you!

[sean-perkins]

This feature is completed and will be available in 6.3.0. This feature request will auto close once it is merged and released. Thanks Hans for the assist!

[liamdebeasi]

Closing as it is completed via #25702. Only PRs that get merged into the default branch cause issues to autoclose it seems.

[ionitron-bot]

Thanks for the issue! This issue is being locked to prevent comments that are not relevant to the original issue. If this is still an issue with the latest version of Ionic, please create a new issue and ensure the template is fully filled out.