detach method
Removes browser behavior when the owning terminal unmounts.
Implementation
void detach(Object owner) {
if (!identical(_owner, owner)) return;
_owner = null;
_connect = null;
_reconnect = null;
_disconnect = null;
_clear = null;
_focus = null;
_write = null;
_send = null;
_copySelection = null;
_connectionState = TerminalConnectionState.closed;
}