So, with https://gerrit.automotivelinux.org/gerrit/c/src/agl-compositor/+/24663 we should be able to use the remoting plug-in but it seems that upstream doesn't expose/install the plugins headers for other users of libweston (outside of libweston)

We therefore should:

• modify meson build files for the plugings (remoting/pipewire one)
• install some build header for libweston which could tell us before hand if the respective functionality is installed or not. 

CC jsmoeller