QTI 2.1: Excel import includes feedbacks

for a QTI 2.1 question several feedback options are available. These options cannot be imported with an excel file. 

The import should be possible for 4 feedback options (see appendix). the "Bedingtes Feedback" will not be added. 

Add new rows 3, 19 and 20 in the excel template (EN and DE)

for 19 and 20: if importing these two rows, the feedback of the question item needs to be added

Inter: CL-779