Fix DNSServer crash

[BlueAndi]

Summary

Because of the changes in #6206 it is necessary to change the QNameLength datatype to uint16_t, to be able to address the QName max. size of 256.

Impact

The problem appears int the following lines from the DNSServer.cpp if QNameLength is 255. The wrap around destroys the following memcpy.

arduino-esp32/libraries/DNSServer/src/DNSServer.cpp

Lines 88 to 93 in b254765

	_dnsQuestion->QName[_dnsQuestion->QNameLength] = 0 ;
	_dnsQuestion->QNameLength++ ;
	// Copy the QType and QClass
	memcpy( &_dnsQuestion->QType, (void*) &_buffer[DNS_HEADER_SIZE + _dnsQuestion->QNameLength], sizeof(_dnsQuestion->QType) ) ;
	memcpy( &_dnsQuestion->QClass, (void*) &_buffer[DNS_HEADER_SIZE + _dnsQuestion->QNameLength + sizeof(_dnsQuestion->QType)], sizeof(_dnsQuestion->QClass) ) ;

[CLAassistant]

All committers have signed the CLA.

[me-no-dev]

thanks @BlueAndi