Api decorator test

[Vortex-21]

Description

Added the basic necessary tests for the api decorator.

Related Issue

https://github.com/dotimplement/HealthChain/issues/74

Changes Made

-Added test to check if the target function is wrapped in the APIMethod instance properly -Added test to check if the "is_service_route" is added as an attribute to the function -Added test to check if the "is_service_route" attribute is set to true or not.

Testing

Checklist

• [x] I have read the contributing guidelines
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [ ] I have made corresponding changes to the documentation
• [x] My changes generate no new warnings
• [x] I have added tests that prove my fix is effective or that my feature works
• [x] New and existing unit tests pass locally with my changes

Additional Notes

[Vortex-21]

I have added the necessary tests for the api decorator . Hope it covers the required range . Please review and ping me up if any changes are required !