Fold a list of HTTP field values into a single string, separated by commas and optional whitespace, as per RFC 9110.
The list of HTTP field values to fold.
Optional whitespace to insert after each comma (default is a single space).
The folded HTTP field value string.
https://httpwg.org/specs/rfc9110.html#rfc.section.5.3
Fold a list of HTTP field values into a single string, separated by commas and optional whitespace, as per RFC 9110.