Add Azure implementation for retrieve access token task:

- add azure storage endpoints
- apply fixes to headerinfo & requestinfo for azure

indexer-service-azure/src/main/java/org/opendes/indexer/azure/util/HeadersInfoAzureImpl.java

@@ -45,10 +45,10 @@ public class HeadersInfoAzureImpl implements IHeadersInfo {
     @Override
     public DpsHeaders getHeaders() {
         if (headersMap == null) {
-            log.info("Headers Map DpsHeaders is null");
-//            headersMap = this.getCoreServiceHeaders(httpHeaders.toSingleValueMap());
+            log.warning("Headers Map DpsHeaders is null");
         }
-        return headersMap;
+        DpsHeaders headers = this.getCoreServiceHeaders(headersMap.getHeaders());
+        return headers;
     }
 
     @Override