This commit rewrites large chunks of the WireGuard protocol handler in order
to simplify the process of importing and exporting configuration. The major
changes are:
1) The wireguard interface configuration tab (General Settings) gained an
import assistant which allows dragging or pasting a native WireGuard
configuration file in order to import required settrings into uci
2) The peer configuration tab gained a similar import assistant which allows
importing the settings for a WireGuard peer from an existing native
WireGuard configuration file
3) The QR code export feature has been rewritten to make the resulting codes
actually useful for importing into a WireGuard client application.
Additionally the plaintext native WireGuard configuration is displayed
to allow copy-pasting it for use on a Linux or OS X system
Signed-off-by: Jo-Philipp Wich <jo@mein.io>
