Fix ResponseHeaderFields.ToString() to emit Connection header from property instead of hardcoding "Upgrade"#12

ReneSchwarzer merged 2 commits intodevelopwebexpress-framework/WebExpress.WebCore:developfrom

copilot/update-documentation-for-installationwebexpress-framework/WebExpress.WebCore:copilot/update-documentation-for-installationCopy head branch name to clipboard