Issue / Use Case

I would like to collect CryptPad Forms responses using mobile devices, such as tablets or laptops, at an in-person community event. The reason is to collect feedback and voluntary contact information from attendees, because registration for the event is not required.

CryptPad currently retains form responses from guest sessions in local storage for review. This is undesirable for my case because a later user of the shared device should not know about or see an earlier user's answers. It's not feasible to clear the browser's cache/storage between users, since that requires an additional step after submission, and I want this to be more scalable to similar events and less-attended devices (e.g. with a browser locked to the form submission page).

Proposal / Implementation

This PR creates an option to bypass saving response history to local storage. The new flow brings the user back to a blank form after submission, with a transient pop-up/toast message informing the user that their submission was saved.

The Q_FORM_SUBMIT message gains a forgetAnonymous property to gate this new behavior, and the editor adds a checkbox managing the property on the document. This checkbox can only be visible and true when the form allows guest submissions with multiple responses are allowed but editing is not allowed.

The form submission notification uses the existing Messages.saved key ("Saved" in English).

The editor changes use two new Messages keys, which are not included in this PR:

1. form_forgetful: A status text blurb in the editor added when the option is enabled. Suggested English text is: "Guests cannot review answers"
2. form_makeForget: A checkbox label for the option in the editor. Suggested English text is: "Prevent guests from reviewing answers"

Please let me know what y'all think and if any changes would help make this acceptable to include in a future release. Thank you!