clock ticks as time events in cpp runtime

[Volker Waurich]

clock ticks should be implemented as time events, not a state events in the cpp runtime

[Rüdiger Franke]

They were originally implemented as time events. They were changed to state events and reverted to time events twice, e.g. in ​https://github.com/OpenModelica/OMCompiler/commit/ddf5050a5843ff64fdff4f4a80cb4daa052de8f1:

 -      _dimTimeEvent = <%timeEventLength(simCode)%>  + _dimClock;
 +      _dimTimeEvent = <%timeEventLength(simCode)%> ;

This commit broke a couple of Modelica_Synchronous examples. It was reverted to time events in ​https://github.com/OpenModelica/OMCompiler/commit/913b58d463b5e881544dca3ad82abbb238f45b2b:

 -      _dimTimeEvent = <%timeEventLength(simCode)%> ;
 +      _dimTimeEvent = <%timeEventLength(simCode)%>  + _dimClock;

We had the blocker tickets #3770, #3771, #3772; two of them are fixed, #3771 reduced in severity.
What more do you want to achieve with this ticket?

Can you please motivate your overall goal and discuss missing features before digging into implementation details?

We should avoid a third big change, followed by revert!!!