[RFC] Add action binder protocol

I'd like to bring attention to this older protocol that was on the mailing list. The idea behind action binding is that you can have clients bind certain actions to events inside a namespace (to avoid conclicts) with the name of the action. There can be global namespaces, as well as namespaces for certain classes of actions such as "media" for media controls, that clients can hook into and respond to. The most obvious, and most immediate use case, is global keybindings. This would allow things such as push-to-talk to work for things such as video/audio teleconferencing.

I did not write this protocol, and I do not have any implementations for it currently, but I hope to start a discussion or at least get some validation that someone else finds this useful. Hopefully so that someone else takes up development.

Previous discussion can be found here: https://patchwork.freedesktop.org/patch/172113/

Signed-off-by: Quentin Glidic sardemff7+git@sardemff7.net