Make the co-sign text on the confirmation page and e-mail configurable

[hlmr-erik]

Thema / Theme

Frontend

Omschrijving / Description

As we would like to integrate the text about co-signing in our regular templates for the confirmation page and e-mail, we would like for these texts to be configurable and to be shown conditionally based on the status of {% cosign_complete %}.

Added value / Toegevoegde waarde

No response

Aanvullende opmerkingen / Additional context

Related to the first item here: https://github.com/open-formulieren/open-forms/issues/3149

Tasks

• [x] Make email text configurable
• [ ] Make confirmation page text configurable