Some errors are not obscured by gRPC server

[SWvheerden]

Attackers can get information about the base node via gRPC errors, even when the
user has set the configuration to obscure the errors.
The particular method that fails to obscure the errors is get_new_block_blob,
where the obscure_error_if_true call is missing:

        let new_block = match 
handler.get_new_block(block_template).await {
            Ok(b) => b,
            
Err(CommsInterfaceError::ChainStorageError(ChainStorageError::InvalidAr
guments { message, .. })) => {
                return Err(Status::invalid_argument(message));
            },
            
Err(CommsInterfaceError::ChainStorageError(ChainStorageError::CannotCal
culateNonTipMmr(msg))) => {
                let status = Status::with_details(
                    tonic::Code::FailedPrecondition,
                    msg,
                    Bytes::from_static(b"CannotCalculateNonTipMmr"),
                );
                return Err(status);
            },
            Err(e) => return Err(Status::internal(e.to_string())),
        };

Errors related to the serialization of the blob also will not be obscured:

        let mut header_bytes = Vec::new();
        BorshSerialize::serialize(&header, &mut 
header_bytes).map_err(|err| Status::internal(err.to_string()))?;

There are also other inconsistencies in the usage of the obscure_error_if_true
method. For example, the majority of invalid arguments are not obscured, possible
to let the requester know what they must correct for their request to succeed. But
some, like errors related to the public key serialization in get_shard_key, are
obscured:

        let public_key = PublicKey::from_bytes(&request.public_key)
            .map_err(|e| obscure_error_if_true(report_error_flag, 
Status::invalid_argument(e.to_string())))?;