Replace all calls to access by gnupg_access
* common/sysutils.c (gnupg_access): New. Replace all calls to access by this wrapper. * common/homedir.c (w32_shgetfolderpath): Change to return UTF-8 directory name. (standard_homedir): Adjust for change. (w32_commondir, gnupg_cachedir): Ditto.
Also use SHGetFolderPathW instead of SHGetFolderPathA on Windows.
This is required to correctly handle non-ascii filenames on Windows.
- GnuPG-bug-id: T5098