[Release][v1.15.1] Quality of life changes

Lite release. This update offers some minor improvements/customizations to the app. Next release will be more substantial.

Changelog

• Finally implemented the download feature for videos.
• Fix some minor UI bugs (incorrect description, minor font issues)
• Long-tapping an image will show the option to share the image instead of the URL. Tapping on share will share that image file directly. This behavior can be reverted to the previous behavior in Settings > Misc.
• Show a warning message when commenting on a post/comment that is over 2 days old. This can be changed in the settings (Misc > Warn when reviving old posts) to a different threshold or disabled altogether.
• Add setting to use a less dark background when using a dark theme.
• Support extremely nested threads (eg. https://lemmy.ca/post/8820716). The app should fully support any degree of nesting no matter how big or small the device screen is. A new action has also been added to the comment menu. A comment can be "opened" so that it is the default depth. This will make it easier to read extremely nested threads.

Update

Some bugs were reported with the release. Release has been bumped to v1.15.1 to address some of the bugs.