Add common token picker on Add Token screen

Shows the top 25 tokens by market cap as clickable buttons
below the contract address input. Clicking a token fills in
its contract address automatically.

src/popup/index.html

@@ -384,6 +384,15 @@
                     id="add-token-info"
                     class="text-xs text-muted mb-2 hidden"
                 ></div>
+                <div class="mb-2">
+                    <label class="block mb-1 text-xs text-muted"
+                        >Or pick a common token:</label
+                    >
+                    <div
+                        id="common-token-list"
+                        class="flex flex-wrap gap-1"
+                    ></div>
+                </div>
                 <div class="flex gap-2">
                     <button
                         id="btn-add-token-confirm"