Restrict which files are inlined within the per-environment directory

Currently puppet's catalog terminus will inline metadata for anything within the per-environment code directory. However, puppetserver's ACL will only allow static content to be retrieved if the path is of the form $codedir/environments/<environment>/modules/*/files/**.

Usually that is the case. However, if a user specifies a environment.conf with a custom modulepath, then it's possible for the resolved file path to be of the form $codedir/environments/<environment>/site/role/**, where role is interpreted as the module name. As a result, we will inline file metadata, but puppetserver will refuse to serve file content.

We need to be more restrictive and only inline metadata for files of the form:

$codedir/environments/<environment>/*/<module>/files/**.