Fix bugs that were causing simulations to fail with exceptions

[daniel-thom]

Fixes the following bugs:

• Exporting transformer taps in QSTS simulation failed on the second time step.
• A few example projects failed because they did not match the input structures introduced in #82
• A few example projects failed because they (by design) did not produce certain export values and the project post-processor didn't handle that.
• Two controllers had incorrect interfaces.