Do not tab complete if command not owned by FAWE

[JeffP07]

Overview

Stops FAWE from trying to fill in tab completes for commands it doesn't own

Fixes #1912

Description

Adds a check if the command owner for the command is FAWE

Submitter Checklist

Beta Give feedback

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

[JeffP07]

Oops made a mistake with the PR