CopyDirWithTemplates - Handles Gotemplate processing and writing.

EnsureDirectory checks if a directory exists and creates it if it doesn't.

EnsureFile checks if a file exists and creates it if it doesn't.

Exists returns whether the given file or directory exists or not.

SymlinkWithFallback attempts to symlink a file or directory, but falls back to a move operation in the event of the user not having the required privileges to create the symlink.