Fixing various test issues for all tests

[YunchuWang]

pipelines tests are failing, this pr fixes flaky tests and any test setup issues

Issue describing the changes in this PR

This pull request includes several important changes to the client module, specifically in the build.gradle file and the IntegrationTests.java file. The changes aim to improve the test setup and enhance the robustness of the integration tests.

Build Configuration:

• Updated the PATH_TO_TEST_JAVA_RUNTIME definition to use the system environment variable JDK_11 or fall back to the system property java.home if the environment variable is not set. (client/build.gradle)

Integration Tests Enhancements:

• Added a @BeforeEach method to delete the task hub before each test to ensure a clean state. (client/src/test/java/com/microsoft/durabletask/IntegrationTests.java)
• Added a delay in the multiInstanceQuery test to account for potential clock drift between client and backend timestamps. (client/src/test/java/com/microsoft/durabletask/IntegrationTests.java)
• Improved the assertions in the multiInstanceQuery test to provide more detailed failure messages and ensure accurate filtering of instances based on timestamps. (client/src/test/java/com/microsoft/durabletask/IntegrationTests.java)
• Adjusted the CreatedTimeFrom and CreatedTimeTo criteria in the purgeInstanceFilter test to account for potential timing issues. (client/src/test/java/com/microsoft/durabletask/IntegrationTests.java)
  resolves #issue_for_this_pr

Pull request checklist

• My changes do not require documentation changes
  • Otherwise: Documentation issue linked to PR
• My changes are added to the CHANGELOG.md
• I have added all required tests (Unit tests, E2E tests)

Additional information

Additional PR information