Draft: Restrict number of edges to edit in one transaction for less trusted users

This reverts 7e1314fc as that approach made people's work cumbersome (see T375122#10203041 and T376301 for side effects).

Instead, only block UI and API transactions if performed by less trusted users && if the number of changes within the single transaction passes a certain threshold (independent from getMaximumSelectionSize() which also takes into account the total number of already existing edges which we do not want).

Bug: T375122

Bug: T376301