feat: add search icon to accessible autocomplete, make hint text aligned correctly

app/frontend/styles/_accessible-autocomplete.scss

@@ -5,12 +5,22 @@
 
 .autocomplete__input {
   font-family: inherit;
+  background-image: url("data:image/svg+xml,%3Csvg class='app-search__icon' width='20' height='20' viewBox='0 0 27 27' fill='none' xmlns='http://www.w3.org/2000/svg' aria-hidden='true' focusable='false'%3E%3Ccircle cx='12.0161' cy='11.0161' r='8.51613' stroke='currentColor' stroke-width='3'%3E%3C/circle%3E%3Cline x1='17.8668' y1='17.3587' x2='26.4475' y2='25.9393' stroke='currentColor' stroke-width='3'%3E%3C/line%3E%3C/svg%3E");
+  background-repeat: no-repeat;
+  background-size: 1em 1em;
+  background-position: 7px center;
+  padding-left: govuk-spacing(6) !important;
 }
 
 .autocomplete__option__append {
   font-weight: bold;
 }
 
+.autocomplete__hint {
+  font-family: inherit;
+  padding-left: govuk-spacing(6) !important;
+}
+
 .autocomplete__option__hint {
   display: block;
   color: $govuk-secondary-text-colour;