Ref. V-SIM.06

Describe the bug

As an admin, while setting up a question inside an election, I can set up a description for this question, that isn't used for anything

To Reproduce
Steps to reproduce the behavior:

1. Sign in as admin
2. Go to a question form in an election
3. Fill the description with "anything"
4. Publish all
5. Go to the frontend
6. Try to find "anything"

Expected behavior
To not have this useless input

Screenshots

Extra data (please complete the following information):

• Decidim Version: 0.27.0.dev

Additional context
This should be also deleted from other places besides the form (like the model, database, GraphQL API if it's there)