load extralibs when expanding monaco. fixes #3319

[Steve-Mcl]

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)

Proposed changes

Ensure extra libs are declared in monaco to prevent red error underline on libraries declared in setup tab.

See issue #3319

Checklist

• I have read the contribution guidelines
• For non-bugfix PRs, I have discussed this change on the forum/slack team.
• I have run grunt to verify the unit tests pass
• I have added suitable unit tests to cover the new/changed functionality

[coveralls]

Coverage remained the same at 67.361% when pulling b5e48aa on Steve-Mcl:fix-monaco-expanded into b14c42b on node-red:master.