DNS-over-HTTPS and DNS-over-TLS support

[abhinavsingh]

Describe the solution you'd like
https://en.wikipedia.org/wiki/DNS_over_HTTPS
https://en.wikipedia.org/wiki/DNS_over_TLS

[abhinavsingh]

Fixed by https://github.com/abhinavsingh/proxy.py#cloudflarednsresolverplugin and https://github.com/abhinavsingh/proxy.py#customdnsresolverplugin

See related PR #671