Add Vector3 extensions to Vector2

[Paul-1379]

Add these vector3 extensions to vector2:

• ChangeX(float x), ChangeY(float y), ChangeZ(float z)
• Clamp(Vector2 min, Vector2 max)
• Lerp(Vector2 begin, Vector2 end)
• InverseLerp(Vector2 begin, Vector2 end)
• LimitLength(float length = 1f)