significantly refactor presentational components

src/components/presentational/Narrative/Adjust.js

@@ -0,0 +1,16 @@
+import React from 'react'
+
+export default ({ isDisabled, direction, onClickHandler }) => {
+  return (
+    <div
+      className={`narrative-adjust ${direction}`}
+      onClick={!isDisabled ? onClickHandler : null}
+    >
+      <i
+        className={`material-icons ${isDisabled ? 'disabled' : ''}`}
+      >
+        {`chevron_${direction}`}
+      </i>
+    </div>
+  )
+}