Update Document Search icon and add SVG asset

Changed the icon for the 'Document Search' entry in
`nav-config-dashboard.tsx` from `ic-cart` to `ic-doc-search`.
Added a new SVG file `ic-doc-search.svg` containing the
markup for the updated icon.

src/client/dd-hub-react/public/assets/icons/navbar/ic-doc-search.svg

@@ -0,0 +1,3 @@
+<svg width="24" height="24" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg">
+    <path d="M20 19.59V8l-6-6H6c-1.1 0-1.99.9-1.99 2L4 20c0 1.1.89 2 1.99 2H18c.45 0 .85-.15 1.19-.4l-4.43-4.43c-.8.52-1.74.83-2.76.83-2.76 0-5-2.24-5-5s2.24-5 5-5 5 2.24 5 5c0 1.02-.31 1.96-.83 2.75zM9 13c0 1.66 1.34 3 3 3s3-1.34 3-3-1.34-3-3-3-3 1.34-3 3"></path>
+</svg>

src/client/dd-hub-react/src/layouts/nav-config-dashboard.tsx

@@ -27,7 +27,7 @@ export const navData = [
   {
     title: 'Document Search',
     path: '/doc-search',
-    icon: icon('ic-cart'),
+    icon: icon('ic-doc-search'),
   }
   //#region example pages
   // {