Fix width issue in Embed Code sample (#40616)

frontend/src/metabase/css/core/width.module.css

 :global(.w-full),
-.w-full {
+.w-full,
+.wFull {
   width: 100%;
 }

frontend/src/metabase/public/components/EmbedModal/StaticEmbedSetupPane/CodeSample.tsx

@@ -61,7 +61,12 @@ export const CodeSample = ({
           ) : null}
         </div>
       )}
-      <div className="bordered rounded shadowed relative mt2">
+      <div
+        className={cx(
+          "bordered rounded shadowed relative mt2",
+          CS.overflowHidden,
+        )}
+      >
         <AceEditor
           className={CS.z1}
           value={source}