This fixes issues causing buffer over-read that leak heap content:
- RESP packet field default left over for COM_LIST
- RESP packet upsert filename
- OK packet message
- RESP packet for stmt row data
- ps_fetch_from_1_to_8_bytes
- ps_fetch_float
- ps_fetch_double
- ps_fetch_time
- ps_fetch_date
- ps_fetch_datetime
- ps_fetch_string
- ps_fetch_bit
- RESP packet for query row data (just possible overflow on 32bit)
It also adds various protocol tests using a new fake server.
