CATROID-1339 "Add to backpack" option missing for "Define" bricks

[friendo97]

Definitionbricks for Userdefined Bricks now have the option "add to backpack" in their context menu

https://jira.catrob.at/browse/CATROID-1339

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[bengaal]

Please consider my suggestion above, otherwise the PR looks good to me.

[bengaal]

Requested changes were implemented, looks good to me!

[dandrawes]

Thank you!