Add delete endpoint for options from questions

[aniri]

This will be used when editing forms.

Add a new endpoint DELETE ​/api​/v1​/form​/section​/{sectionId}/question/{questionId}/option/{optionId}

When called, the link between the option and the question should be removed from the optionsToQuestions table.

If that option was not used by other questions, it should also be removed from the options table.

[DSVDavid]

I can take this