TMPE: Why do option tabs OWN the options. They shouldn't.

_Originally posted by @kvakvs in https://github.com/CitiesSkylinesMods/TMPE/pull/1370#pullrequestreview-874101969_

The big question for a separate PR: Why do option tabs OWN the options. They shouldn’t.

This is a good point. Additionally all code should reference options the same way - currently some code refers to fields in Options.cs while other code is querying checkboxes and other stuff in the various tabs files.