Updating libclamunrar from legacy C implementation to modern unrar 5.6.5. API changes and supporting changes included to pass the filepath of the scanned file into libclamav through the cli_ctx structure, required by the unrar library to open archives. The filename argument may be optional for the scandesc scanning variant, but libclamav will make a best effort to identify the filename from the file descriptor if it was not provided. In addition, included the ability to prefix temp file and directory names with file basenames.