Fixes for MTK v8

[ValentinKaisermayer]

Changes

• Blocks make use of a connector in the form of a RealInput and RealOutput (as Modelica does). However, this could be improved since there is only one variable in the connector. Definitions of input=true and output=true where removed since this feature is not fully developed in MTK. Can be added later in one place.
• Where applicable Electrical components make use of OnePort.
• Where applicable Thermal components make use of Element1D.

Still open

• Tests for Magnetic
• PID-controller and StateSpace block
• A bunch of math blocks e.g. Tan
• A bunch of source blocks e.g. Square
• Doc strings
• Port names, parameter names and component names should be as in the Modelica standard library. The goal would be that existing Modelica examples can be almost copy pasted.

[ChrisRackauckas]

Can we get to a merge point and then do a different PR to update the other things? I think too many PRs in this repo have been big "fix all of the things" PRs that never got merged, that then stopped other people from contributing as they waited for someone to finish a "fix all of the things" PR. So a "here's MTK v8" with 7 issues of harder things to update, that's a much better option in my book IMO, unless you plan to really knock out that list in a week.

[ChrisRackauckas]

Deleting the tests is definitely a bad thing. We won't be able to merge this with those older tests removed.

[ValentinKaisermayer]

Deleting the tests is definitely a bad thing. We won't be able to merge this with those older tests removed.

I re-added explicit tests for the sim results of the analog sources, first and second order systems. I also added them for the block sources. I hope this will be sufficient.

I also added a first test for the magnetic domain. However, most of the magnetic components are still not covered.

[ChrisRackauckas]

The only tests I see are missing are the digital tests. Those are commented out. With those back I think this is ready to merge.

[ValentinKaisermayer]

The only tests I see are missing are the digital tests. Those are commented out. With those back I think this is ready to merge.

They are commented out in the current release as well.

[ChrisRackauckas]

Okay cool, amazing. Just noticed that. I think it's fine to merge this and call it v1.0, and further improvements will continue to happen, but this is a major step forward already and at least 1000x better than what we had before. Major props to @ValentinKaisermayer !