fix(Docker): use cert chain for nginx

Additionally, simplify some of the certificate generation scripts and rename ca.ext to localhost.ext.

Certificates should be regenerated as of this commit. Users can run rm -rf ./cache/* to clear out any existing certs, which will cause the ca service to regenerate them.

Additionally, since Docker infrastructure has been modified, a new aurweb:latest image will need to be built.

See https://gitlab.archlinux.org/archlinux/aurweb/-/wikis/Docker

Signed-off-by: Kevin Morris kevr@0cost.org