Inform when vector api is present but not used

[SirYwell]

Overview

Description

Inform the user when they already use the --add-modules flag for the vector api but haven't enabled it in FAWE.

Submitter Checklist

• Make sure you are opening from a topic branch (/feature/fix/docs/ branch (right side)) and not your main branch.
• Ensure that the pull request title represents the desired changelog entry.
• New public fields and methods are annotated with @since TODO.
• I read and followed the contribution guidelines.