[BugFix] - Allow kwargs on POST endpoints

[IgorWounds]

1. Why? (1-3 sentences or a bullet point list):

   • Passing kwargs was broken for POST endpoints which hindered the development and user experience.

2. What? (1-3 sentences or a bullet point list):

   • Handles the kwargs parameter and type hint on the package builder. Now kwargs can be passed and used.

3. Impact (1-2 sentences or a bullet point list):

   • No noticeable impact. Allows for kwargs being passed when defined on the router.

4. Testing Done:

   • Tested that the kwargs work and are being passed.