Add stack coloring to the debugger

[jecisc]

This PR add some stack coloring to the debugger.

Now the stack has 3 different text colors:

• One when the context of a stack element is from the same class than the selected context
• One when the context of the stack element is from the same package than the selected context
• And the default text color otherwise

This is especially useful when debugging some pattern such as visitors or composites...

I wanted to add an info popup to describe the feature but I didn't find a way to display text in Spec, just strings.

THIS REQUIRES: pharo-project/pharo#13693

[StevenCostiou]

Changes are ok.
There are tests failing because of the changes though.

[jecisc]

This is because the Pharo PR has not been reviewed and integrated yet. I’ll restart it when it will be the case.

[StevenCostiou]

Would it be possible to have a setting to (de)activate the coloring?
I guess the next step (after that PR) would be to have a system to custsomize the coloring? :P

[jecisc]

I can check to do that when I'll have the time

For the customization, I made it part of the theme. So user can create their own theme. We can also see to improve the default values Pharo's theme if someone has knowledge on color palette.

Another idea would be to have in the setting the possibility to customize all colors of the theme but this is out of the scope of this feature :)

[StevenCostiou]

For the customization, I meant customizing what to highlight and under what conditions.
From there why not choosing the color from their application or directly in their customization.

[jecisc]

Would it be possible to have a setting to (de)activate the coloring? I guess the next step (after that PR) would be to have a system to custsomize the coloring? :P

Done!

[StevenCostiou]

Thanks Cyril!
A few comments, but seems good otherwise.

[Ducasse]

Cool. I just mentioned to Cyril that we should pay attention with too pale (or not even intense colors) because of color blind people. There are software that simulate what the color blind people can see and this is nice to try. We did it for the mooc template.