A strict version of [func@header_parse_param_list] that bails out if there are duplicate parameters.
Note that this function will treat RFC5987-encoded parameters as duplicated if an ASCII version is also present. For header fields that might contain RFC5987-encoded parameters, use [func@header_parse_param_list] instead.
header |
a header value |
a GenericSet of list elements, which can be freed with [func@header_free_param_list] or null if there are duplicate elements. |