Native v9.1.0

You can now download videos from the lightbox and see the channel host on the Channel Info screen. This release also fixes broken group invite notifications, .HEIC photo uploads with HDR data, and the message long-press menu not dismissing on tap.

• Adds a download button to the video player lightbox to download.
• Adds support for sending notifications for when others react to your posts.
• Adds the channel host on the Channel Info screen.
• Reorders the sign-up options on the initial app launch screen.
• Removes automatic joins for new users to the public Tlonbot demo group.
• Fixes an issue where tapping a group invitation push notification would fail to route to the invite.
• Fixes an issue where uploading .HEIC photos with HDR data would fail.
• Fixes an issue where tapping to dismiss the message long-press menu would fail.