JUCE GUI: unused checkButtonWidth in addRadioButtons + "ciruclar" typo

[PrateekSingh070]

Two small things in architecture/faust/gui/JuceGUI.h:

1. In addRadioButtons (around 1878) there’s a TODO: "check currently unused checkButtonWidth...". The code computes checkButtonWidth from the max label width but then never uses it - the layout uses fixed kCheckButtonWidth / kRadioButtonHeight. So either the computed width should be used for layout, or the variable and loop can be simplified.

2. Line 1899: comment says "Add a ciruclar slider" - typo, should be "circular".

[PrateekSingh070]

@sletz please look into this issue