Button: get focusWidth and arc from UI defaults

flatlaf-core/src/test/resources/com/formdev/flatlaf/FlatTestLaf.properties

@@ -29,6 +29,7 @@ Button.startBorderColor=ff0000
 Button.endBorderColor=0000ff
 Button.disabledBorderColor=000088
 Button.focusedBorderColor=466d94
+#Button.arc=10
 
 Button.default.background=dddddd
 Button.default.foreground=880000
@@ -41,6 +42,8 @@ Button.default.focusColor=ff0000
 #---- Component ----
 
 Component.focusColor=97c3f3
+#Component.focusWidth=5
+#Component.arc=8
 
 
 #---- Label ----