sdbus++: enhance exception information

Use both 'name' and 'description' for exceptions.  All sdbusplus
exceptions now have a 'name()' and 'description()' method which
give the dbus error name and a human-readable description
respectively.  The standard 'what' is now '<name>: <description>'.

Change-Id: Ic6cdb88350c07589cbfbf233e84a575632383af6
Signed-off-by: Patrick Williams <patrick@stwcx.xyz>
4 files changed