fix(tooltip): remove text-shadow to avoid inheritance from parent

To avoid accidental inheritance of styling from parent element, text-shadow: none is explicitly set for [data-tooltip] popup.

Author: exoego

src/definitions/modules/popup.less

@@ -108,6 +108,7 @@
     position: absolute;
     text-transform: none;
     text-align: left;
+    text-shadow: none;
     white-space: nowrap;
 
     font-size: @tooltipFontSize;