verification/rvgen: Allow spaces in and events strings

verification/rvgen: Allow spaces in and events strings

Currently the automata parser assumes event strings don't have any
space, this stands true for event names, but can be a wrong assumption
if we want to store other information in the event strings (e.g.
constraints for hybrid automata).

Adapt the parser logic to allow spaces in the event strings.

Reviewed-by: Nam Cao <namcao@linutronix.de>
Link: https://lore.kernel.org/r/20260330111010.153663-4-gmonaco@redhat.com
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>