LibGUI: Give some widgets a reasonable default fixed height

Instead of hard-coding 22 in random places, just make the following
widgets have a fixed height of 22 by default: Button, CheckBox,
ColorInput, ComboBox, RadioButton, SpinBox, TextBox.

In the future we can make this relative to the current font size,
but for now at least this centralizes the setting a bit better.

Libraries/LibGUI/CheckBox.cpp

@@ -39,6 +39,7 @@ static const int s_box_height = 13;
 CheckBox::CheckBox(String text)
     : AbstractButton(move(text))
 {
+    set_fixed_height(22);
 }
 
 CheckBox::~CheckBox()