Improve and add support for multiple database environments in the integration tests .

Description

• Stabilize integration-test user provisioning and privilege setup.
• Align credential and connection tests with supported environments.
• Make Oracle error assertions portable across JDBC and database versions.
• Stabilize synthetic-data tests and document their test setup.

How Has This Been Tested?

• Unit test suite (All tests pass)
• Integration test suite (All tests pass)

Test Configuration:

• Firmware version:
• Hardware:
• Toolchain:
• SDK:

Checklist:

• My code follows the style guidelines of this project
• I have performed a self-review of my own code
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes
• Any dependent changes have been merged and published in downstream modules