Function
get-trailer-names
Gets the names of the trailers associated with this body.
The first cursor names are skipped. The remaining names are encoded successively with
a NUL byte after each into a list of bytes at most max-len long. If any of the remaining
names don't fit, the returned option<u32> is the index of the first name that didn't fit,
or none if all the remaining names fit. If max-len is too small to fit any name, an
error.buffer-len error is returned, providing a recommended buffer size.
get-trailer-names: func(body: borrow<body>, max-len: u64, cursor: u32) -> result<tuple<string, option<u32>>, trailer-error>;