Allow non-registered users to register for meetings

Is your feature request related to a problem? Please describe.
Requiring an account to register for a meeting can deter a portion of our potential audience, especially those who are new to the platform or hesitant to commit. This limitation restricts the diversity and scale of participation, which runs counter to our goal of fostering inclusive civic engagement.

Describe the solution you'd like
To lower this barrier, users without an account would be able to join meetings if the admin allow so and would just have to enter their name, email and their consent to receive emails. After submitting the form, they're registered for the meeting and a confirmation email is sent. The option to allow for people to sign up for a meeting without an account should be managed from the configuration page of every meeting.

Describe alternatives you've considered

Having an intermediary page for people that are not signed in and want to join a meeting trying to convince them to sign up. But this would just add an extra step and value of the account would be unclear.

Additional context

Add any other context or screenshots about the feature request here.

Does this issue could impact on users private data?
Ex. issues related with user's sign up/sign in process, verifications, invitations, sensitive data like email, IP addresses, etc.

Funded by
OSP and our clients (co-financing is very welcome to make this feature as nice and long-term as possible)