server: remove dbus_find_interfaces
server: remove dbus_find_interfaces

This can be a blocking call, so refactor discovery such that an
org.freedesktop.Properties.Get call is invoked at discovery time
for instrospected objects with associations.

Change-Id: I9c4d54bbc3834c7970eac23cba4045fc4dd0cd6a
Signed-off-by: Brad Bishop <713d098c0be4c8fd2bf36a94cd08699466677ecd@fuzziesquirrel.com>

bradbishop/phosphor-objmgr,bradbishop/phosphor-objmgr,openbmc/phosphor-objmgr,openbmc/phosphor-objmgr,bradbishop/phosphor-objmgr