readLink function
Implementation
void readLink(String data, LinkState out) {
// Upstream: `third_party/ultraviolet/styled.go` (`ReadLink`).
// OSC 8 format: ESC ] 8 ; params ; url ST
// Here `data` is the portion after "8;" in our parser.
final firstSep = data.indexOf(';');
if (firstSep < 0) return;
final params = data.substring(0, firstSep);
final url = data.substring(firstSep + 1);
out.link = Link(url: url, params: params);
}