Arguments could be captured even when signature is unknown

Consider functools.lru_cache; this is a built-in, so signature is not available. However, we still get args and kwargs if we trace the call (as happens often when the decorator is used on a traced class). Currently in the absence of a signature parameters end up being []. I think it's worthwhile to record arguments anyway.

Requires applandinc/appmap#22

For all intents and purposes blocked by #126 -- in CPython native functions are, to my knowledge, the only case where a function signature cannot be obtained. While it might be possible to implement and even test this without that, but it would be pretty useless.

Inizia esaminando il percorso di acquisizione degli argomenti per le chiamate tracciate che coinvolgono functools.lru_cache, quindi verifica la dipendenza in applandinc/appmap#22 e l’issue bloccante #126. Il lavoro è completato quando args e kwargs vengono registrati anche quando non è disponibile alcuna firma della funzione, invece di lasciare parameters vuoti.