more mypy

[altendky]

catch up of https://github.com/Chia-Network/clvm/pull/107

Broad Concerns:

• [x] various code results in different exceptions being raised in unexpected cases. for example, an AssertionError if an object is None where previously a TypeError would have been raised where we take the len() of the object.
• [x] hinting around internal complex stack-related activities that... i should probably mostly accept failure on and ignore

Draft For:

• [x] TODO:s
• [x] naming suggestions raised in https://github.com/Chia-Network/clvm/pull/125#discussion_r1402135298
• [x] reviewing explicit concerns above

[coveralls-official[bot]]

Pull Request Test Coverage Report for Build 8424848351

Details

• 237 of 253 (93.68%) changed or added relevant lines in 11 files are covered.
• 1 unchanged line in 1 file lost coverage.
• Overall coverage decreased (-1.1%) to 93.997%

---

Changes Missing Coverage	Covered Lines	Changed/Added Lines	%
clvm/CLVMObject.py	15	16	93.75%
clvm/EvalError.py	4	5	80.0%
clvm/as_python.py	38	39	97.44%
clvm/op_utils.py	6	7	85.71%
clvm/run_program.py	18	19	94.74%
clvm/serialize.py	29	30	96.67%
clvm/SExp.py	34	36	94.44%
clvm/more_ops.py	49	51	96.08%
clvm/operators.py	29	35	82.86%
<!--	Total:	237	253

Files with Coverage Reduction	New Missed Lines	%
clvm/operators.py	1	65.47%
<!--	Total:	1

Totals
Change from base Build 8162235751:	-1.1%
Covered Lines:	994
Relevant Lines:	1044

---

💛 - Coveralls