Stamp target URL and timestamp into HTML report header

[noVaSon]

🚀 Summary

Stamps the target base URL (CAT_FC_HOST) and a UTC timestamp into the HTML report
title at the start of each test run. This makes the report self-evidently prove which
deployment instance was under test, without requiring a separate sidecar file.
The injection uses behave-html-formatter's set_title(append=True) API and runs
once globally via before_all.

This change is part of the Enhancement of XFSC Federated Catalogue. Details can be found here (permalink):
https://github.com/eclipse-xfsc/docs/blob/f3c6e6b6fbcc87732a1dfe83f060fa58a9a97873/federated-catalogue/src/docs/CAT%20Enhancement/CAT_Enhancement_Specifications%20v1.0.pdf

✅ What's Changed

• Feature implemented / Bug fixed
• Documentation updated (if needed)
• Tests added or updated
• Code formatted and linted

🧪 How to Test

1. Ensure CAT_FC_HOST is set (e.g. export CAT_FC_HOST=https://qa.example.com).
2. Run the HTML report target: make run_cat_bdd_dev_html
3. Open .tmp/behave/behave-report.html in a browser.
4. Verify the report header reads:
   Behave Test Report — https://qa.example.com @ <UTC timestamp>

🔍 Related Issues

Closes #
Related to #

📸 Screenshots (if applicable)

📋 Checklist

• I've tested my code locally
• I've added tests if needed
• I've updated documentation if necessary
• My changes follow the project's coding style