BUG: Add support for GBK2K cmaps (#2385) #4180

Job	Run time
pytest on windows	4m 43s
Check code style issues	20s
Build & verify package	17s
pytest on 3.7 (crypto-lib: cryptography)	3m 24s
pytest on 3.8 (crypto-lib: cryptography)	3m 37s
pytest on 3.9 (crypto-lib: cryptography)	3m 31s
pytest on 3.10 (crypto-lib: cryptography)	3m 29s
pytest on 3.11 (crypto-lib: cryptography)	3m 13s
pytest on 3.12 (crypto-lib: cryptography)	4m 43s
pytest on 3.7 (crypto-lib: pycryptodome)	3m 29s
pytest on 3.7 (crypto-lib: none)	3m 38s
Combine & check coverage.	13s
	34m 37s

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