include simFasBui in every model that needs any of these inputs

[saroele]

We now have several building models for single zone buildings, depending on which heating system is used. The heating system can be redeclared, but depending on the control strategy etc it needs different inputs, and that's why we need all these models.

Instead, we could include the outer simFasBui in the heating model, and connect internally. Redeclaring the heating would then automatically include the correct connections and we would largely simplify the 'Buildings' subpackage.