A missing XDG_RUNTIME_DIR results in ENOENT, like on the server
side.
A too long name results in ENAMETOOLONG, like on the server side.
When we can't find the socket, return EHOSTDOWN to make it more
obvious what is going.
The pw_remote object is really a wrapper around the pw_core_proxy.
The events it emits are also available in the core proxy and are
generally awkward to use.
With some clever new pw_core_proxy_* methods and a pw_core_connect
to create the core_proxy, we can convert all code away from pw_remote.
This is a first step in this conversion, using the pw_remote behind
the scenes. It leaks into some places because it really needs to become
its own struct in a next step.
Make pw_remote_connect_fd() not automatically close the provided
fd but let the caller take care of that. This allows us to reuse
the fd in pipewiresrc.
Fixes#155
Make the protocol client connect call async with a callback when it
completes.
Move the connect methods into separate files, add an empty connect
method that will use the screencast portal to get a pipewire fd.
Use the remote intention to get the connect method.
Add some better error reporting.
