Refactor the PKCS11 CryptoCanDo implementation

[ionut-arm]

This issue covers a cleanup of the implementation of CryptoCanDo in the PKCS11 provider. Some comments from #426 :

• methods on types can be called directly on self, so for example Provider::import_check(&self, attributes) can be replaced with self.import_check(attributes).

• use_check is partially implemented in can_do_crypto_internal - the match arm that covers the use verification does a check before calling the method, which could be moved inside the method

• is the last return from can_do_crypto_internal needed if the match before it is exhaustive?