For all project attributes, you can check a `required_for_all_projects` checkbox. If checked, the project attribute cannot be disabled for any project. It is always enabled for a project. Also, the attribute must have a value set and cannot be blank.

Since Calculated Values perform a calculation, they can potentially always be blank. Maybe because a calculation error happens (division by zero). Or because a required field from a formula is not set. As a consequence, if the value for another custom field is blanked in the section modal, this could lead to a Calculated Value being blank and thus throwing a generic "value can't be blank" error... We don't want that.

### Acceptance Criteria

* If `required_for_all_projects` is checked for a Calculated Value

* It is **allowed** to have a **blank** **value**

* It will always be enabled for all projects and cannot be disabled (default behavior for all project attributes) Begin of the insertion

* Additionally:

* hide calculated required fields from the project creation form.

* trigger calculations after a project is created.End of the insertion