Parallelize address scanning and unify address display formatting

Scanning: check all gap-limit addresses in parallel per batch instead
of sequentially. For a wallet with 1 used address this reduces from
12 sequential RPC round-trips to 1 parallel batch + 1 small follow-up.

Display: add shared formatAddressHtml(address, ensName, maxLen) and
escapeHtml() to helpers.js. Use them in confirm-tx (was missing color
dot entirely) and approval view. Remove duplicate escapeHtml from
addressDetail.js.

src/popup/views/approval.js

@@ -1,4 +1,4 @@
-const { $, addressDotHtml } = require("./helpers");
+const { $, formatAddressHtml } = require("./helpers");
 const { state, saveState } = require("../../shared/state");
 
 const runtime =
@@ -14,8 +14,11 @@ function show(id) {
             return;
         }
         $("approve-hostname").textContent = details.hostname;
-        const dot = addressDotHtml(state.activeAddress);
-        $("approve-address").innerHTML = dot + state.activeAddress;
+        $("approve-address").innerHTML = formatAddressHtml(
+            state.activeAddress,
+            null,
+            null,
+        );
         $("approve-remember").checked = state.rememberSiteChoice;
     });
 }