[assemblyscript] Optimize & refactoring

[MaxGraey]

No description provided.

[Tugcga]

Ok, there is only one small bug after refactoring. But I will fix it.

Also it seem that there is a bug in the StaticArray class. slice function return Array class instead of StaticArray (here). But static version of this function returns proper class, so it can be used instead of the class method.

[MaxGraey]

Also it seem that there is a bug in the StaticArray class. slice function return Array class instead of StaticArray

It's not a bug. But use static variant StaticArray.slice(static_arr, ...) which return StaticArray instead Array