Add e2e of helm registry in JH

What does this MR do and why?

Add E2E test cases in JH: helm registry

override read_fixture in JH

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.

/cc @prajnamas