UnrealTraceServer exits when encountering a symlink on Windows

UnrealTraceServer exits on startup (or when watching a directory) when a watched store directory contains a symlink on Windows.

Cause: The std::filesystem::directory_entry::is_directory() call throws an unhandled exception.

1. On Windows, create a symlink in a watched directory on an NTFS filesystem. One way is to create it with WSL. The symlink target file does not need to exist.

   cd /mnt/c/Users/user.name/AppData/Local/UnrealEngine/Common/UnrealTrace/Store/001
   ln -s target link
   

2. Start UnrealTraceServer.exe daemon

Observation: UnrealTraceServer prints the settings then terminates.
Expectation: UnrealTraceServer continues running as a daemon.