Actions should consume data instead of using them as reference

[oblique]

I want to move a non-clonable data from an event to the next state. This is currently not possible because data are passed as references in action's parameters.

An example of what I'm trying to do:

pub struct NonClonableData;

smlang::statemachine! {
    transitions: {
        *State1 + Event1(NonClonableData) / state1_event1_action = State2(NonClonableData),
        // ...
    }
}

struct Context;

impl StateMachineContext for Context {
    fn state1_event1_action(&mut self, event_data: NonClonableData) -> NonClonableData {
        event_data
    }
}

If you are willing to review and possibly merge a PR that passes the data as owned values, then I can implement this on my free time. This of-course will be a breaking change.