Add new AutoScaler and CustomScalerBase classes #7000

Job	Run time
Check code formatting (Black)	29s
Check Spelling	8s
Compatibility tests	4m 34s
Pylint	4m 9s
Build Sphinx docs	5m 36s
pytest (py3.9/linux)	20m 50s
pytest (py3.9/win64)	30m 19s
pytest (py3.10/linux)	14m 1s
pytest (py3.10/win64)	32m 49s
pytest (py3.11/linux)	19m 47s
pytest (py3.11/win64)	40m 45s
pytest (py3.12/linux)	12m 15s
pytest (py3.12/win64)	26m 25s
Upload coverage report (Codecov) (linux)	9s
Upload coverage report (Codecov) (win64)	9s
	3h 32m 25s

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