Button: undone most style changes done in previous commit related to focused and default buttons:

- default button: white background and wide border
- focused button: light blue background and thin border

(the light blue default button did not look beautiful IMHO)

flatlaf-testing/src/main/resources/com/formdev/flatlaf/testing/FlatTestLaf.properties

@@ -76,6 +76,8 @@ Button.disabledBorderColor = #008
 Button.focusedBorderColor = #466d94
 Button.hoverBorderColor = #f00
 
+Button.innerFocusWidth = 1
+
 Button.default.startBackground = #ddd
 Button.default.endBackground = #888
 Button.default.foreground = #800