This will launch 'rclone webdav server' passing random TLS
certificate and username/password and serve predefined rclone
remote path.
This is very experimental, use with caution.
Fixes#313.
Additional / required changes:
* blob: (experimental) support for rclone provider
* server: refactored TLS utilities to separate package
* webdav: add support for specifying trusted TLS certificate fingerprint
* kopia-ui: added rclone support
7ae823945c