The oslo::service defined type was added a long ago but has never been
used by any other modules so far. The main blocker is that the type
manages not only common service parameters but also wsgi/ssl parameters
which are specific to api services.
This change splits the defined type to smaller modules so that we can
reuse the implementation.
Because the defined type is not used by any other modules at this
moment, and we don't expect direct usage of these resource type(*1),
this change is backword-incompatible.
(*1)
Technically it can be used but cause multiple conflicts.
Change-Id: If524155bf2d0dda964c6b451d7b26f36481514f5
19862b0f18