Fast zero-allocation universal hash function

[destel]

This pull request adds a fast generic hash functions that can be used in MapOf. This allowed to make two new constructors that do not require user to specify hash function manually

func NewUniversalMapOf[K comparable, V any]() *MapOf[K, V]
func NewUniversalMapOfPresized[K comparable, V any](sizeHint int) *MapOf[K, V]

The core idea behind is to create generic higher order function that can construct hash func for a specific comparable type.

hash := MakeHashFunc[string]()
seed := maphash.MakeSeed()
fmt.Println(hash(seed, "foo"), hash(seed, "bar"))

MakeHashFunc uses some reflection under the hood, but resulting function it produces is very fast zero-allocation hasher that's based on some unsafe magic (the same way as hashers that already exist in this package).

Below are the becnhmarks for different types

BenchmarkMakeHashFunc/int_hash-12                   1000000000           0.9810 ns/op          0 B/op          0 allocs/op
BenchmarkMakeHashFunc/string_hash-12                311438284            3.841 ns/op           0 B/op          0 allocs/op
BenchmarkMakeHashFunc/xsync_test.Point_hash-12      442970949            2.739 ns/op           0 B/op          0 allocs/op
BenchmarkMakeHashFunc/*xsync_test.Point_hash-12     1000000000           0.9841 ns/op          0 B/op          0 allocs/op

[destel]

Thank you very much for the feedback

[puzpuzpuz]

@destel many thanks on your contribution!