www/{nginx,nginx-devel,freenginx}: 3rd-party modules management

Copy the module sources with cp instead of COPYTREE_SHARE in the
LUA and LUASTREAM pre-configure targets. COPYTREE_SHARE hardlinks
the files and then fails to chmod them when poudriere builds as an
unprivileged user.

Convert www/nginx-module-lua into a pure source-only port. The
prebuilt DSO conflicted with the module built by the nginx ports.

Add compat patches so lua-nginx-module builds against freenginx.

PR: 297651
Reported by: Brad Ackerman
Sponsored by: Netzkommune GmbH