Update Read and Append testcases - CLDCONNECT-2159

JIRA ID - CLDCONNECT-2159 - https://www.mulesoft.org/jira/browse/CLDCONNECT-2159

1. ReadTestCases and flow in automation-test-flows has been refactored since read is an inbound endpoint now.
2. AppendTestCases has been refactored to take into account the changes to automation-test-flows.