Core changes:
* avoid package-colliding variable naming
* avoid using pointers to IDs where unnecessary
* avoid using `idSDK` import alias pattern
* use `EncodeToString` for protocol string calculation and `String` for
printing
Signed-off-by: Leonard Lyubich <leonard@nspcc.ru>
If the key can't be fetched, an error is always returned, so it makes
sense to fail the whole command inside of a `key.Get*()`.
Signed-off-by: Evgenii Stratonikov <evgeniy@nspcc.ru>
