patches/netdata: Add netdata integration

Adds Netdata into webapps. Also set up lighttpd to act as a proxy with pam authentication for it and disable unauthenticated network access. This way netdata is available on IP/netdata only after entering a password.

Webapps are currently our specific and lighttpd as well, so generally not upstreameable but we can give it a shot once we will have a newer webapps and try to uupstream those.