Hashmap Versions Save

• improved hashing and avoid dedicated MapString type

• optimized hashing by separating string support into separate type
• removed all external dependencies

• optimize hashing by Inlining hashing as anonymous functions
• reduce allocations for write operations

• fix hashing on ARM CPUs
• optimize hashing by using specialized xxhash implementations
• reduce variable allocations in get functions
• removed obsolete 0 length checks

It is noticeable faster than the current version of HaxMap is able to handle collisions of valid 0 hash values:

BenchmarkReadHashMapUint-8                	 1314156	       955.6 ns/op
BenchmarkReadHaxMapUint-8                 	  872134	      1316 ns/op (can not handle hash 0 collisions)

// works for this library, fails for HaxMap
func TestHash0Collision(t *testing.T) {
	m := New[string, int]()
	staticHasher := func(key string) uintptr {
		return 0
	}
	m.SetHasher(staticHasher)
	m.Set("1", 1)
	m.Set("2", 2)
	_, ok := m.Get("1")
	if !ok {
		t.Error("1 not found")
	}
	_, ok = m.Get("2")
	if !ok {
		t.Error("2 not found")
	}
}

• fixed insert during map grow
• fixed add not working properly during concurrent delete
• add SetHasher function to allow setting of a custom hasher
• benchmarks have been moved to a subdirectory to remove imports for external libraries from main module

• CAS has been removed as it is not working
• Iter function signature has been changed to Range
• all comparable key types are supported now

• fix hash collision handling
• switch library to use generics
• minor API changes
• CAS is currently not supported
• removed []byte key support

• Fixed delete action when using hashed key
• Fixed race condition in list