cubicweb-vcsfile #2794142 clarify local_cache handling wrt path value [validation pending]

As of today, a repo with a source_url will get a "local cache" clone, but a repo with a "path" (reachable through the filesystem) has none.

The original use case for "path" => no local_cache may have been a misguided attempt at disk space optimisation. I believe the local_cache should always be there.

prioritynormal
typeenhancement
done in2.0.0
load0.200
load left0.000
closed by<not specified>