Delete record form

[chs8691]

The user expects, that he can delete the record on the edit page. For this, there must be a button 'Delete'. A record may only be deleted, if there are no materials assigned. If there are assigned materials, a message should be shown 'There are assigned materials, the record can't be deleted.'

When the record is deleted successful, a success message on the following page has to be shown 'Record 2019-01-01 deleted'.