feature: Allow hiding specific fields in the registration form (#367)

[VitorVieira20]

Add option to hide fields in the registration form

Fields that can be hidden:

• Phone
• Position
• Organization

Behavior for required fields:

• These fields can now be toggled on or off in the project settings under the "Registration" section.
• If any of these fields are marked as required, the hide setting will be ignored, and the field will still be displayed in the form.
• Closes Remove/hide the organization and position #367