PR summary

closes #20355

Added PowerTransform and PowerScale, to make PowerNorm using the make_norm_from_scale decorator.

In PowerNorm the expected behavior is normalizing before transformation, unlike other scales which transform and then normalize. So I added a optional boolean argument norm_before_trf to make_norm_from_scale which controls whether normalization occurs before transformation or not.

PR checklist

• "closes #0000" is in the body of the PR description to link the related issue
• new and changed code is tested
• Plotting related features are demonstrated in an example
• New Features and API Changes are noted with a directive and release note
• Documentation complies with general and docstring guidelines