Function parse_vuint 

pub fn parse_vuint(input: &[u8]) -> IResult<&[u8], u64>

Parse unsigned VInt64 for Cassandra timestamps

Matches org/apache/cassandra/io/util/DataInputPlus.readUnsignedVInt() Used for timestamp deltas and other 64-bit unsigned values.

Encoding format:

• Leading 1-bits indicate number of extra bytes
• Pattern: [n ones][0][data bits]
• Example: 0xxxxxxx = 1 byte, 10xxxxxx xxxxxxxx = 2 bytes
• Maximum 8 extra bytes (9 bytes total) for full 64-bit range

Arguments

• input - Input byte slice

Returns

Tuple of (remaining_bytes, decoded_u64_value)