URIUtils: add 'CanonicalizePath' function
WIN32Util::ConvertPathToWin32Form: update to resolve relative paths
WINSMBDirectory::GetDirectory: unify with other code and use WIN32Util::ConvertPathToWin32Form
Merge pull request #3447 from Karlson2k/win32_fix_relative_paths

[Win32] fix relative paths, fixes #14812