zeroconf: Unvalidated rdlength in record payload readers allows LAN-local cache corruption via crafted mDNS packet

Impact readcharacterstring and readstring in src/zeroconf/protocol/incoming.py sliced self.dataself.offset : self.offset + length and advanced self.offset by the declared length without checking it against self.datalen. Python's slice silently returns fewer bytes when the end index runs past the...