Print to file in debug mode

[hecmas]

This pull request introduces a feature to optionally print debug information to a file instead of standard output.

Key changes include:

Command Structures:

• Added a new boolean flag print_to_file to ProveCmd and VerifyConstraintsCmd structs to enable printing debug information to a file.

Mode Initialization:

• Updated the StdMode struct and its constructor to include the print_to_file flag.
• Modified StdMode::new calls to accommodate the new print_to_file parameter.

Debug Printing:

• Enhanced the print_debug_info function to handle writing to a file if the print_to_file flag is set, including creating the necessary directory and file.
• Updated calls to print_debug_info in StdProd and StdSum implementations to pass the print_to_file flag.

These changes ensure that debug information can be optionally redirected to a file, improving flexibility and usability in different debugging scenarios.