Add a specialization of FileSystemConnector that delays computing the binary value's SHA-1 hash

Continuation of issues on:
https://issues.jboss.org/browse/MODE-2061

LargeFileSystemConnector - for federation of directories of large static files

When using option contentBasedSha1=false, the BinaryValue key is a hash of the path URL rather than the content, improving lookup performance. This connector generates a lazy (computed when asked for) hash of content when the key is a hash of the URL.