Bind/run multiple actions at once

[YaLTeR]

Allow binds to run several actions sequentially, e.g.:

Mod+G {
    focus-column-right
    consume-or-expel-window-left
}

And, more importantly, add some way to run several actions as a batch through IPC and niri msg action. This will allow doing several actions as one atomic sequence and with no delay in-between, which is currently impossible.

Here the binds and the IPC part should be straightforward, but I'm not sure how to parse the arguments in niri msg action. Maybe clap offers something?

Another question is what to do if only one action in the sequence fails a check like allow-when-locked. Here I guess we ignore just the action that fails the check, same as what would happen if you were to run several niri msg action commands one after another.

[YaLTeR]

Idea from @calops for CLI:

you could also just have an option to read actions from stdin, where you can just put all of them separated with newlines

Though, I'm not sure if you can run a clap parser on stdin to parse the arguments.

[calops]

You should be able to run a clap parser on any string manually. It would have to be a subset of the global parser but it sounds doable.