Add Unit and Integration Tests

[hasanxdev]

This PR focuses on adding unit tests, improving CI/CD, and updating code coverage processes. Here’s a brief overview of the changes:

Unit & Integration Tests:

• Added tests for DispatchR configuration, handler registration, handler inclusion/exclusion, and empty handler arrays.
• Created tests for generic pipeline registration and StreamRequestHandler.
• Renamed tests for clarity and added notification registration tests.
• Added tests for new pipeline behaviors, updated service registration logic, and covered integration tests.

CI/CD & Code Coverage:

• Updated build-release.yml to conditionally run steps for versioned tags and include coverage reports in Codecov actions.
• Upgraded Codecov action to version 5 and improved token handling.
• Consolidated unit and integration tests in a single step with coverage collection.
• Updated coverlet packages to version 6.0.4 and modified test commands for better coverage collection.
• Added Codecov badge in README.md for coverage tracking.

In summary, this PR enhances unit and integration test coverage, refines the CI/CD pipeline, and focuses on Codecov integration and coverlet configuration.

[codecov]

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