feat: allow arbitrary response for suggester

[QRuhier]

For suggester question only outside table, add the possibility of chosing to allow an arbritrary response.

It is quite close to clarification question for code lists, but instead of adding a list ClarificationQuestion in the question, we create a single object ArbitraryResponse.

• on a suggester question, the user only has to chose if he wants to allow arbitrary response
• when generating collected variables (in collected variables panel), it also generates an arbitrary variable (the user can then update its name/label) => by default, the name of the variable is ${questionName}_ARBITRARY, and its label is ${questionName}_ARBITRARY label

[QRuhier]

⚠️ do not merge until Eno dev is done

[QRuhier]

I forgot to update some tests after some renames, will be fixed tomorrow

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
60.0% Coverage on New Code
0.0% Duplication on New Code

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