["FEAT"] In app purchase support

[felipemontoya]

Is your feature request related to a problem? Please describe.
we want to support inapp purchases from the https://github.com/openedx/openedx-app-ios and android apps.

Describe the solution you'd like
At this point we want to have a placeholder for the discussions

Describe alternatives you've considered
finding a plugin from wordpress or woocomerce that already does the ios/google verification of receipt part. Then we want to connect that to the order fullfilmment process

Additional context

• put the image from the conference in person discussion
• interested people @volodymyr-chekyrta @MaferMazu @sdaitzman @marcotuts @feanil

[MaferMazu]

Note: We need to send a confirmation response to Apple and Google to verify the purchase on the mobile app.