Fix TypeError in version display by adopting importlib.metadata

[sauravkeshrii]

Description

This PR fixes a critical bug in rvctool.py where the script called version('package-name') – but the version function takes no arguments, leading to a TypeError at startup.

The issue is resolved by replacing the erroneous calls with the standard importlib.metadata.version('package-name') method, which reliably retrieves the installed version of any Python package. A helper function get_version gracefully handles missing packages by returning "not installed", preserving the original behaviour.

Additionally, the auto‑generated rvc3python.egg-info/ directory has been added to .gitignore to keep the working directory clean and prevent accidental commits.

Changes

• Added import importlib.metadata
• Introduced get_version(pkg_name) helper
• Replaced all version(...) calls with get_version(...)
• Updated .gitignore to ignore rvc3python.egg-info/

Testing

• Verified that the script now runs without the TypeError
• Confirmed version strings display correctly for installed and missing packages

This fix makes the tool more robust and user‑friendly for everyone.