[Lazarus] Groupboxes in the IDE

[theo]

> Well, it's doing that already by using the Label & 2xBevel isn't it??
Yes, I counted these as "//groupbox-alikes" too in my prev. message.

I don't mind if you use custom components for the IDE if there is a good reason to do so.
But you should be aware of the fact that they do not follow themes with the current solution.

As long as both (TGroupBox, custom groupbox) are used together, 
it may look inconsistent mainly because of different caption-font.


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