Add editor hint support for trace

[arimer]

Fixes #974

[alexanderpann]

Did you mean !isTraceHintAvailable() in the is applicable block? Otherwise, you set the hint only when it is already set.

[arimer]

Might, be. Let me check.

[arimer]

Now you made me think if we do even want to check in the editor hint in the precondition of the action. I don't think we want to deactive the action if the hint is already set. 🤔

[mgronover]

I found the following points:

1. The menu entries "show trace" and "stop trace" causes an influence on user settings in editor hints.

2. I would suggest that we do not need a second point to activate/deactivate the trace explorer "show trace"/"stop trace". The Toolbar of the TraceExplorer can be used to hide the decorated code:
   

I totally agree with the editor hint for the Tracing Editor. The reason is explained here: #1005

So I would prefer using the approach of #1005.

[arimer]

drop in favor of #1005