wallet: (fix) cannot just piggyback on adb.is_up_to_date()

The wallet needs its own up_to_date logic:
- the adb being up_to_date means all its addresses are synced
- but an HD wallet might decide to roll the gap limit and generate new addresses
  - the adb does not know about this...
  - the wallet should be considered *not* up_to_date
- relatedly, it is now the wallet that decides to reset the network request counters

- note that wallet.main() was never cleaned up previously.
  - now wallet gets its own taskgroup, which is cleaned up in wallet.stop.

Follow-up to adb refactor: 121d8732f1

electrum/address_synchronizer.py

@@ -672,12 +672,6 @@ class AddressSynchronizer(Logger):
         with self.lock:
             status_changed = self._up_to_date != up_to_date
             self._up_to_date = up_to_date
-        # reset sync state progress indicator
-        if up_to_date:
-            if self.synchronizer:
-                self.synchronizer.reset_request_counters()
-            if self.verifier:
-                self.verifier.reset_request_counters()
         # fire triggers
         util.trigger_callback('adb_set_up_to_date', self)
         if status_changed:
@@ -686,6 +680,12 @@ class AddressSynchronizer(Logger):
     def is_up_to_date(self):
         return self._up_to_date
 
+    def reset_netrequest_counters(self) -> None:
+        if self.synchronizer:
+            self.synchronizer.reset_request_counters()
+        if self.verifier:
+            self.verifier.reset_request_counters()
+
     def get_history_sync_state_details(self) -> Tuple[int, int]:
         nsent, nans = 0, 0
         if self.synchronizer: