Add support 128bit hash

[C0deUser]

Hello!

Please, add support 128bit hash (unsigned int)

from rbloom import Bloom
from xxhash import xxh3_128_intdigest

bf = Bloom(10_000, 0.01, xxh3_128_intdigest)
bf.add("hello")                             # Gives this error: OverflowError - int too big to convert 

I use next workaround as suggested in your example:

from rbloom import Bloom
from xxhash import xxh3_128_digest

def hash_func(obj):
    hash_bytes = xxh3_128_digest(obj)
    return int.from_bytes(hash_bytes, "big", signed=True)

bf = Bloom(10_000, 0.01, hash_func)
bf.add("hello")

This works as expected.

But surely it shouldn't matter to a Bloom filter whether an integer between -2^127 and 2^127 is 1, or an unsigned integer? A workaround would add overhead.