Fix Cache Control headers on media

See merge request pleroma/pleroma!2295

Change domain, ensure paths to PEM files are correct, and this is good to go.

  since Pleroma.Web.Endpoint binds on IPv4 only and `localhost.` resolves to
  [::0] on some systems

  fixes #930.

[ci skip]

[ci skip]

ssl_trusted_certificate should point to chain.pem if we're demonstrating LetsEncrypt: https://community.letsencrypt.org/t/howto-ocsp-stapling-for-nginx/13611/5

Replaces `listen 80` with `listen [::]:80`, same with 443

Nginx is currently not caching data because proxy_buffering needs to be
enabled for caching to work at all, and we are receiving a Cache-Control
header from Pleroma that states "max-age=0, private, must-revalidate"

Even disregarding the Cache-Control header that should actually be set
to "public, max-age=1209600" as defined in the reverse_proxy code, we
don't want to obey this header at all as it overrides our Nginx caching
rules.

This enables caching/streaming of chunked responses

Support more filetypes for caching static media