This function copies a file from one location to another, with an optional
version suffix appended to the filename.
Usage
copy_file_version(model_path, file_name, file_version = NULL)
Arguments
- model_path
The path to the directory containing the file.
- file_name
The name of the file to be copied.
- file_version
An optional version suffix to be appended to the filename.
Default file_version = NULL, which adds '.bkp' to the filename.
