A significant number of trace calls did not use a parent context that
would create proper span ordering in trace output. Add local context to
functions for use in trace calls to facilitate proper span ordering.
Additionally, change whether trace function returns context in some
functions in virtcontainers and use existing context rather than
background context in bindMount() so that span exists as a child of a
parent span.
Fixes#1355
Signed-off-by: Chelsea Mafrica <chelsea.e.mafrica@intel.com>