Fixes #3697 /claim #3697

Description

This PR implements the datastarRequest extension method for Invocation. It allows generating Datastar expression strings directly from ZIO HTTP Endpoint invocations.

It handles:

• Path parameter interpolation.
• Query parameter serialization.
• JSON body serialization.

Verification

I have run sbt fmt and verified that all tests pass with sbt test.

Demo Video

https://github.com/user-attachments/assets/e2e12560-244f-479d-bdc3-d707e0672511