text: Title: [Feature request] Add balanced scale to `Affine`
  Body: From FAQ https://albumentations.ai/docs/faq/#how-to-perform-balanced-scaling 
  
  
  The default scaling logic in `RandomScale`, `ShiftScaleRotate`, and `Affine` transformations is biased towards upscaling.
  
  For example, if `scale_limit = (0.5, 2)`, a user might expect that the image will be scaled down in half of the cases and scaled up in the other half. However, in reality, the image will be scaled up in 75% of the cases and scaled down in only 25% of the cases. This is because the default behavior samples uniformly from the interval `[0.5, 2]`, and the interval `[0.5, 1]` is three times smaller than `[1, 2]`.
  
  To achieve balanced scaling, you can use the OneOf transform as follows:
  
  ```python
  balanced_scale_transform = A.OneOf([
    A.Affine(scale=(0.5, 1), p=0.5),
    A.Affine(scale=(1, 2), p=0.5)])
    ```
  This approach ensures that exactly half of the samples will be upscaled and half will be downscaled.
  
  -----
  We could just add `balanced_scale` to `Affine` that will do it under the hood