This tests exporting a PW_TYPE_INTERFACE_Endpoint and binding
a proxy for it through the registry, verifying that info and params
are propagated properly from one to the other
The proxy API is the one that we would like to expose for applications
and the other API is used internally when implementing modules or
factories.
The current pw_core object is really a context for all objects so
name it that way. It also makes it possible to rename pw_core_proxy
to pw_proxy later.
meson < 0.46 does not allow two targets to share the same name;
meson >= 0.46 relaxes that requirement, but I see no reason to require
a new version of meson just for this