Utils: Rework CheckableMessageBox

Remove function overloads, thes are hard to read, to use and to extend.
I'd even argue this should be a plain default ctor and a few setters +
exec(), pretty much like Process::start() nowadays.

Move "decider" magic into a structure that can be filled ad-hoc outside
checkablemessagebox.cpp paving the ground for:

...removing  aspect dependency from CheckableMessageBox, Instead, add a
convenience function to BoolAspect.  Arguably, the latter is not needed
and could be done on the user side.

Use pointers instead of mutable references for in-out parameter.
Makes the "specialness" visible on the user side.

Pass ICore::settings() centrally as done elsewhere to reduce line noise
on the user side.

Change-Id: Ibb366353d1ea35401723fd05ce05672617a0a8fd
Reviewed-by: Marcus Tillmanns <marcus.tillmanns@qt.io>

src/libs/utils/aspects.cpp

@@ -4,6 +4,7 @@
 #include "aspects.h"
 
 #include "algorithm.h"
+#include "checkablemessagebox.h"
 #include "environment.h"
 #include "fancylineedit.h"
 #include "layoutbuilder.h"
@@ -1358,11 +1359,10 @@ FilePathAspect::FilePathAspect()
     The color aspect is displayed using a QtColorButton.
 */
 
-ColorAspect::ColorAspect(const QString &settingsKey)
+ColorAspect::ColorAspect()
     : d(new Internal::ColorAspectPrivate)
 {
     setDefaultValue(QColor::fromRgb(0, 0, 0));
-    setSettingsKey(settingsKey);
     setSpan(1, 1);
 
     addDataExtractor(this, &ColorAspect::value, &Data::value);
@@ -1587,6 +1587,14 @@ void BoolAspect::setLabelPlacement(BoolAspect::LabelPlacement labelPlacement)
     d->m_labelPlacement = labelPlacement;
 }
 
+CheckableDecider BoolAspect::checkableDecider()
+{
+    return CheckableDecider(
+        [this] { return !value(); },
+        [this] { setValue(true); }
+    );
+}
+
 /*!
     \class Utils::SelectionAspect
     \inmodule QtCreator