feat: add strong typing for ModalController dismiss values

[RoopeHakulinen]

Feature Request

Ionic version:
[x] 4.x

Describe the Feature Request
Currently the dismissal data of a shown modal is not typed. onWillDismiss uses the following signature:

'onWillDismiss': () => Promise<OverlayEventDetail<any>>;

OverlayEventDetail already supports the parametrization but any type is specified here. Instead it could be using a type specified when creating the modal so this

const modal = await this.modalController.create({
  component: EditDeviceSettingsPage
});
await modal.present();
const { settings } = await modal.onWillDismiss().then(({ data }) => data);
// settings is of type any

would become

const modal = await this.modalController.create<Settings>({
  component: EditDeviceSettingsPage
});
await modal.present();
const { settings } = await modal.onWillDismiss().then(({ data }) => data);
// settings is of type Settings

Describe Preferred Solution
Add type parameter for ModalController::create to specify the possible value returned upon dismissal.

Additional Context
This would not improve the typing in the modal component itself as it could still dismiss anything it wishes. I cannot foresee any chance to improve that with the current design but this would at least improve the ergonomics on the parent.

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Thank you!

[tawfiek]

Interested .. I will investigate in this

[brandyscarney]

Thank you for the issue! This has been done with the following PR: #21393

Please let me know if this doesn't solve your use case and I will reopen, thanks!

[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.