Add outfit name to Shopping List page title

Just some extra flair! I had considered something like this before, but
felt it didn't flow well with the old title.

app/javascript/wardrobe-2020/WardrobePage/ItemsPanel.js

@@ -295,14 +295,20 @@ function GetTheseItemsButton({ outfitState }) {
     }
   }, [searchParams, setIsVisible]);
 
-  const itemIds = [...outfitState.wornItemIds].sort();
-  const targetUrl = `/items/sources/${itemIds.join(",")}`;
-  const isDisabled = itemIds.length === 0;
-
   if (!isVisible) {
     return null;
   }
 
+  const itemIds = [...outfitState.wornItemIds].sort();
+  const isDisabled = itemIds.length === 0;
+
+  let targetUrl = `/items/sources/${itemIds.join(",")}`;
+  if (outfitState.name != null && outfitState.name.trim().length > 0) {
+    const params = new URLSearchParams();
+    params.append("for", outfitState.name);
+    targetUrl += "?" + params.toString();
+  }
+
   return (
     <Tooltip
       label="Shopping list"

app/views/items/sources.html.haml

@@ -1,5 +1,7 @@
-- title "Shopping List"
-%h1#title Shopping List
+- page_title = params[:for] ? "Shopping List for \"#{params[:for]}\"" : "Shopping List"
+
+- title page_title
+%h1#title= page_title
 
 :markdown
 	Here's a custom shopping list for exactly the items in your outfit!