[DC-7967] - Increase test coverage and address PR-Commenter Recommendations and outdated dependencies

[tyagikumarvineet]

Description - Code changes to increase test coverage and address PR recommendations and outdated dependencies

Below have been covered as part of this PR

• Increase test coverage by adding new test classes and add tests in existing Test classes
• update the libraries' version
• update build.sbt config and fix warnings
• update the minimum test coverage to 86% in build.sbt
• test coverage is 91.25% on Jenkins now
• add a constant file named TestData for the common test data
• below have been updated in Integration tests
  replace message microservice routes with secure-message microservice routes to make use of secure messages
  instead of messages
  remove usage of obsolete endpoint http://localhost:8910/test-only/qmessages
• minor refactoring