- add IsValidCodePage in WinFctHelper to check whether code page number is valid.
- add 6 macros to batchly (add / set default) (move / copy) (constructor / assign operator).
- add default or delete (copy / move) (constructor / assign operator) for some classes.
- use namespace bracket all content in documentation to reduce useless namespace prefix.
- change the argument type of AbstractSetting and CoreManager to yycc_u8string_view instead of const yycc_char8_t*.
- throw exception if given setting name is invalid in ConfigManager, instead of slient fallback.
- rename Constrain to Constraint in code and documentation.
- remove massive annotation of encoding helper because the documentation is enough.
- fix doxygen character shift warnings.
