Add delete functionality for saved qr codes

[DcGabriel707]

No description provided.

[danielPerez97]

It's worth pointing out that Scoped Storage in Android is here/coming. It's an overhaul to file storage on Android and it has a lot of developers upset, plus I think it's getting it's full release in Android 11.

That is to say, I'd wait on this one, but I agree it needs to be done. I think it is better to wait for the full scoped storage rollout/Android 11 Beta and see how it's going to be handled officially, including waiting for their library that will backport for you(AppCompat library style).