Proper RTL support (#1154)

* Add RTL styles. Most of the work is done by the browser 💖

* Refactor getLanguage

* Additional fixes

* Mirror the mouse pointer icon

* Move the vertical scrollbar to the left on RTL

* Revert "Mirror the mouse pointer icon"

This reverts commit f69b132538038d231b1b1acc0d6f4a28c91130bb.

src/components/ToolIcon.scss

@@ -149,3 +149,12 @@
     }
   }
 }
+
+.unlocked-icon {
+  :root[dir="ltr"] & {
+    left: 2px;
+  }
+  :root[dir="rtl"] & {
+    right: 2px;
+  }
+}