REST: For enumerate, use GetObject for target path

Make a call to GetObject for the target path to get its
connection names and interfaces to add to the GetSubTree
results data before looking for object managers in the
GetSubTree data.  This is the only way that the code can
find an object manager interface on the target path.

Tested: /enumerate works better

Change-Id: I341b2f46ee7a20793b5f2db15bf4b57b0cbc6d01
Signed-off-by: Matt Spinler <spinler@us.ibm.com>