[native] Upload encrypted media to Blob service
Summary:
The final diff that enables encrypted media uploads to Blob service on native.
I decided to hide this feature behind a boolean flag to be able to easily flip the switch.
Test Plan: Set the useBlobServiceUploads to true. Send a message with image, video, multiple media (mixed images and videos). Verify they're sent successfully. Verify Blob service content (S3 + DynamoDB) and keyserver uploads table. Logged out and in to reset local cache. Media are still loaded correctly.
Reviewers: atul, marcin
Reviewed By: atul
Subscribers: ashoat, tomek
Differential Revision: https://phab.comm.dev/D7650