Well, those "lines" are headers (which may actually span multiple physical lines), with a name ('Sec-WebSocket-Extensions' and 'Forwarded' respectively), and a value ('permessage-deflate; client_max_window_bits; server_max_window_bits=10, permessage-deflate; client_max_window_bits', and 'for=1.2.3.4;host="foo.ba;r",for=5.6.7.8,for=9.10.11.12;host=bar.foo' respectively).
If you are referring to tokenization and and formatting of structured values of such headers, then MIME.tokenize and MIME.quote should be your friends. The detailed interpretation of the actual tokens would be specific to the header at hand though.
Parsing headers from "lines" can be done with MIME.Message, which can also format them back into "lines", but there is also Protocols.HTTP.Query.headers_encode for that. And of course if you are using Protocols.HTTP to make/process requests the module will take care of this for you.