Fix timeout/prepend mod read fixtures

What does this MR do and why?

Since the foreign source in the QA pipeline cannot be accessed, we need to overwrite the configuration file and modify the source address on the JH side.

1. Add prepend mod and override read_fixtures method.
2. Copy config file to JH and change source address.

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