[Feature] add `.!`

[hamidb80]

like ! operator when you confident about the presence of the value:

let s = some "Hello"
echo s.!len

[markspanbroek]

Thanks for the suggestion @hamidb80! I'm not sure whether the .! would be useful for most cases. You can already use (!s).len, and chaining it like you would with .? (a.?b.?c) is not necessary, because you already remove the optional at the first step.