Improve redundancy in text fields while using "convert to nifti" feature in selective transfer

[chinacat567]

##216 (comment)
Currently, the following text fields can be selected alongside the convert to nifti flag -

• Trial ID
• Trial name
• Pseudonym
• Archive password

These are no longer required because nifti files do not contain patient data and hence pseudonymization is not applicable.

Find a way to decouple this, either by un-selecting or redesign the UI

[medihack]

I think just disabling them would work the best (then the user doesn't loose any input if he decides not to use Nifti).
If nifti conversion is activated, we can also skip the manipulation of the temporary DICOM files.