Use PathTree as internal storage structure
Use PathTree as internal storage structure

PathTree enables more efficient and more idiomatic iterating.
Also tweaked the org.openbmc.objectmanager interface methods:
removed 'fuzzy' match type and added 'GetObject'.

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