feat: EventValues from heterogenous tuples

[sgasse]

So far, we were only able to serialize Vec<T> or iterators of T for one homogenous type T. Users were forced to pre-create an EventValue::List with inner EventValues.

This commit adds From implementations for tuples ranging from 2 to 5 elements where each type can be a different one as long as all of them implement Into<EventValue>.

Example event description

# application: string
# duration: int, milli seconds
00000007 app_ready (application|3),(duration|1|3)

# before
let value = EventValue::List(vec![
    EventValue::String("app1".to_owned()),
    EventValue::Int(Duration::from_secs(7).as_millis() as i32),
]);
write_event_now("module_tag", ).unwrap();

# now
write_event_now("module_tag", ("app1", Duration::from_secs(7).as_millis() as i32)).unwrap();