[C2] Registration: Option to select between learner and teacher in registration form does not appear

[ywarnier]

When registration.allow_registration_as_teacher is true (and registration.allow_registration is true), the registration form (to create a new account) should offer 2 roles: teacher and learner. If registration.allow_registration_as_teacher is false, this option does not appear.

Currently, we lost this possibility with the new registration form.

In C1, it looked like this (but don't use the same icons as they are out of the current design line. Use ObjectIcon::USER and ObjectIcon::TEACHER).

[christianbeeznest]

It is checked and improved with this PR #7183

Thanks for confirmation.

[ywarnier]

Tested and approved. Thanks.