feat(button): circular icon button to appear round at minimum

Whenever a circular icon button was used to reduce the padding but use text instead of an icon, the button does not appear as a circle at least (that is taken care of for circular label)

By adding a min width to a circular button this gets fixed.
I intentionally added the minwidth directly to circular button (instead of circular icon button) as it saves an extra selector and the default min-width is already reached (because of the larger paddding) when a non icon button is used.

Author: lubber-de

src/definitions/elements/button.less

@@ -1098,6 +1098,7 @@
     .ui.ui.circular.buttons .button,
     .ui.ui.ui.ui.circular.button {
         border-radius: @circularBorderRadius;
+        min-width: @circularMinWidth;
     }
 
     .ui.circular.buttons .button > .icon,

src/themes/default/elements/button.variables

@@ -394,6 +394,7 @@
 /* Circular */
 @circularBorderRadius: 10em;
 @circularIconWidth: 1em;
+@circularMinWidth: 2.5em;
 @circularGroupMargin: 0.25em;
 @circularVerticalGroupMargin: @circularGroupMargin;