Consider removing `IPdfFormatter`

[bjosttveit]

IPdfFormatter was a feature primarily made for the old PDF generator, but was preserved to make migrating to the new one easier. The reason for using this, was mainly that dynamics did not run on the old PDF generator, so if you needed to dynamically hide components you had to implement the same show/hide logic for the PDF generator using IPdfFormatter. This is no longer an issue as this is covered out-of-the-box with expressions, but you could still use it for additional visibility logic if you want to do special things only in PDF.

The IPdfFormatter interface has already been marked as obsolete for a while.

Before deciding on whether to remove this feature or not we should check how it is used today for apps in v8. It is unfortunately not trivial to automatically migrate any logic from here.