fix: a popup reload no longer logs the requests it cancels on most screens (closes #475)

The transaction lists and ENS name lookups on the address and token
screens, the address scan after a wallet is created, the endpoint checks
in Settings, the wait screen's receipt check, the Send screen's Max fee
estimate and the token lookup on both add-token screens now check the
signal the popup aborts on pagehide before reporting a failed request.
scanForAddresses(), resolveEnsNames() and lookupTokenInfo() take the
signal.

End-to-end tests reload the popup on the address screen and during the
address scan with their requests held. Jest tests show each of these
reports a real failure and stays silent once the popup has closed. The
transaction detail and confirmation screens are left out: they discard
the popup context that carries the signal.

Model: opus-5-5

src/popup/views/addWallet.js

@@ -190,7 +190,12 @@ async function importMnemonic(ctx) {
 
     // Scan for used HD addresses beyond index 0.
     showFlash("Scanning for addresses...", 30000);
-    const scan = await scanForAddresses(xpub, state.rpcUrl, state.networkId);
+    const scan = await scanForAddresses(
+        xpub,
+        state.rpcUrl,
+        state.networkId,
+        ctx.pageClosed,
+    );
     if (scan.addresses.length > 1) {
         wallet.addresses = scan.addresses.map((a) => ({
             address: a.address,
@@ -300,7 +305,12 @@ async function importXprvKey(ctx) {
 
     // Scan for used HD addresses beyond index 0.
     showFlash("Scanning for addresses...", 30000);
-    const scan = await scanForAddresses(xpub, state.rpcUrl, state.networkId);
+    const scan = await scanForAddresses(
+        xpub,
+        state.rpcUrl,
+        state.networkId,
+        ctx.pageClosed,
+    );
     if (scan.addresses.length > 1) {
         wallet.addresses = scan.addresses.map((a) => ({
             address: a.address,