Added all constructs applicable to untraceable SUT

[majeau-bettez]

• Add aPC, ITC, ETC, PSC, BTC, AAC, CTC and LSC
• Dedicated normalization function handles normalizing in (almost) all constructs, handles empty rows/columns, and creates filters (nn_in, nn_out)
• All constructs give the same consistent output: A, S, nn_in, nn_out, Z, F_con
• Automatic generation of primary production matrix (E_bar)
• Automatic generation of subsptitution matrix and alternate activity matrix in multi-regional context
• A certain number of "helping functions" outside of the class definition
• I tried to be thorough on the documentation
• Unit tests for all, in a separate class
• Now compatible with improvements and pull-request from Chris Mutel.