When running swaymsg -v, the version returned is actually the version of
swaymsg itself, yet the message displayed was "sway version <version>".
This can create confusion if users update sway and swaymsg but don't
restart sway, then use swaymsg to check the version.
This patch changes the wording to be "swaymsg version <version>"
instead, and likewise for swaybar.
To get the version of a running sway instance, users should run swaymsg
-t get_version.