[FAB-7383] 2. Support affiliations REST API

This change implements all the affiliations
REST API calls to the fabric-ca.

Change-Id: If6827dd85de9b53fe905beccc96b60c7cec36a1e
Signed-off-by: Saad Karim <skarim@us.ibm.com>

Author: Saad Karim

src/main/java/org/hyperledger/fabric/sdk/helper/Utils.java

@@ -49,6 +49,7 @@
 import org.bouncycastle.crypto.digests.SHA3Digest;
 import org.bouncycastle.util.Arrays;
 import org.bouncycastle.util.encoders.Hex;
+import org.hyperledger.fabric_ca.sdk.exception.InvalidArgumentException;
 
 import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.apache.commons.codec.binary.Hex.encodeHexString;