Use iOS 14's PHPickerViewController for device media selection

[bjtitus]

Is your feature request related to a problem? Please describe.
iOS 14 adds a new "Limited" permissions option that complicates the experience a bit:

A prompt is not required as long as the PHPickerViewController is used. See pbArwn-17O-p2 for details and discussions of the permissions prompts.

Describe the solution you'd like
We should be using the PHPickerViewController for selecting media from the users' device.

Describe alternatives you've considered

Additional context
This may need to be part of a bigger project to consolidate the various sources of media pickers into one interface as Android currently does. See pbArwn-1cr-p2

[SergioEstevao]

@bjtitus are you proposing to wrap around PHPickerViewController inside the MediaPicker library?

Or replace the uses of the MediaPicker for accessing the users' device with the PHPickerViewController?

We can do that in the main WP apps but we will need to keep a fallback for the iOS 13 devices.

[bjtitus]

@SergioEstevao Sorry for the lack of detail. This was mostly a stub for a larger discussion about changes we started discussing for stories: pbD5rk-lL-p2

are you proposing to wrap around PHPickerViewController inside the MediaPicker library

I was thinking about this change if we switch to a consolidated UI, where WP Media and device photos are in different tabs. So we would wrap PHPickerViewController and add something like WPNavigationMediaPickerViewController but with multiple datasources with corresponding tabs instead of just one.

I'm drafting up a post with some further details.

[kean]

Covered in wordpress-mobile/WordPress-iOS#21190. I'm going to close this ticket as a duplicate.