Refactor Commands to Handle Default Structure Paths

[httpdss]

Overview:

This pull request refactors the command modules in generate.py and list.py to handle cases where the structures_path argument is not provided, falling back to a default path.

Changes:

• generate.py:
  • Removed the default value for --structures-path argument.
  • Added logic to fallback to a default path (contribs) if no path is provided.
• list.py:
  • Modified the list command to handle optional structures-path.
  • Implemented fallback logic to default contribs directory when no path is specified.

Justification:

This refactor allows for greater flexibility when using the commands by enabling the user to provide custom paths for structure definitions or rely on the default path if none is supplied.

Impact:

• Improves the robustness of the commands by ensuring default paths are used if the user does not explicitly specify a path.
• Simplifies the interface for users running commands without additional configuration.