Add optional namespace arguments for `make_class` #720

Job	Run time
Build docs & run doctests	28s
Check types using pyright	28s
Tests & Mypy on 3.7	36s
Verify dev env (ubuntu-latest)	17s
Tests & Mypy on 3.8	1m 0s
Verify dev env (windows-latest)	43s
Tests & Mypy on 3.9	1m 4s
Tests & Mypy on 3.10	1m 19s
Tests & Mypy on 3.11	1m 18s
Tests & Mypy on 3.12	1m 17s
Tests & Mypy on pypy-3.8	53s
Tests & Mypy on pypy-3.9	56s
Tests & Mypy on pypy-3.10	59s
Combine & check coverage.	13s
required-checks-pass	1s
	11m 32s

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