[v3.0.2] Fix hyperloglog + seedrandom typings

[folkvir]

• fix seedrandom typing Typescript types incompatible with recent versions of @types/seedrandom #72
• fix hyperloglog problems; _hashing.serialize is buggy due to the casting of Number() and toNumber() instead we use directly XXH.h64 with its .toString() function. Hyperloglog Example Not working #69

There are common parts with the v4 update but until we finally release this version we can deploy this one to fix those 2 issues.

[Callidon]

LGTM 🚀