Fix url property format in urls.yml file

What does this MR do?

Fixes the issue where property names in urls.yml file were using colon prefix and YAML.safe_load was throwing an error. Also updates the artillery yml file to use a tcp connection pool.

Does this MR meet the acceptance criteria?

• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides