Fixes#625
* add support for Identity-H/V cmap fonts
* format code to pass flake8 check
* Remove indent
* Remove indent
* Use isinstance instead of type check
* Use or instead of any
* Use str in variable, instead of str.find()
* Fix mypy error: add typing annotations to get_unichr()
* Fix type of PDFCIDFont. Can be any type of CMapBase.
This is a quick fix, the entire cmap structure does not have proper inheritance.
* Added line to CHANGELOG.md
* Add separate class for IdentityUnicodeMap
* Remove ABC from CmapBase
* Remove ABC from CmapBase
* Remove blank line
Co-authored-by: huan_cheng <huan_cheng@bestsign.cn>
Co-authored-by: Pieter Marsman <pietermarsman@gmail.com>
wind_chh