ENH: Improve/rewrite PDF permission retrieval #4261

Job	Run time
pytest on windows	5m 6s
Build & verify package	24s
Check code style issues	41s
pytest on 3.7 (crypto-lib: cryptography)	3m 30s
pytest on 3.8 (crypto-lib: cryptography)	3m 38s
pytest on 3.9 (crypto-lib: cryptography)	3m 50s
pytest on 3.10 (crypto-lib: cryptography)	3m 31s
pytest on 3.11 (crypto-lib: cryptography)	3m 27s
pytest on 3.12 (crypto-lib: cryptography)	4m 53s
pytest on 3.7 (crypto-lib: pycryptodome)	3m 49s
pytest on 3.7 (crypto-lib: none)	3m 25s
Combine & check coverage.	21s
	36m 35s

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