Remove DI Profile
I couldn't find the abbreviation "DI" in the standard documents. Only "DL". I think , "DL" is the valid abbreviation. But for example cimpy/examples/sampledata/CIGRE_MV/Rootnet_FULL_NE_24J13h_DI.xml is named "DI".
I suggest we completely drop the "DI" profile abbreviation in favor of "DL"