fix(react): Make CSS files direction-aware to support RTL layouts

Author: UdeshAthukorala

packages/react/src/components/Header/header.scss

@@ -40,7 +40,7 @@
       height: 40px;
       max-width: 100px;
       display: flex;
-      margin-right: 0.5rem;
+      margin-inline-end: 0.5rem;
 
       img {
         width: 100%;

packages/react/src/components/NavbarItem/navbar-item.scss

@@ -72,7 +72,7 @@
         justify-content: initial;
 
         .oxygen-list-item-icon {
-          margin-right: 10px;
+          margin-inline-end: 10px;
         }
 
         .oxygen-list-item-text {