server: use lambda functions with _invoke_method
server: use lambda functions with _invoke_method

Use lambda functions with _invoke_method to avoid method name lookup
and enable additional state.

Change-Id: If0b702c4d890d0173883f7b144c2ca8dc9d590ee
Signed-off-by: Brad Bishop <713d098c0be4c8fd2bf36a94cd08699466677ecd@fuzziesquirrel.com>
Resolves: openbmc/phosphor-objmgr#14

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