Improve Error Handling for Missing Metadata

[animex007]

Description:
Currently, when metadata is missing in certain parts of the Archweb application, users are not provided with clear error messages. This can lead to confusion and difficulty in troubleshooting. Implementing improved error handling will ensure users receive informative and actionable feedback when metadata is missing.

Benefits:

• Enhances user experience by providing clear guidance.
• Facilitates easier debugging and resolution of issues.

Example:

  if not metadata:
    log_error("Metadata missing for package XYZ.")
    display_error("Required metadata is missing. Please contact support.")

[jelly]

What metadata is missing? Please provide a clear reproducer.