Use http2 and http3 nginx directives

[strarsis]

This PR uses the http2 and http3 directives instead the deprecated http2 keyword in listen directive.
HTTP 2 and HTTP 3 support can be controlled using the ansible http2_enabled and http3_enabled options.

Using the h5bp nginx configuration as base.

As some may still be hesitant to enabling HTTP 3 support in nginx, the
option for HTTP 3 is turned off by default and can be turned on manually.