lnwatcher: add some type hints

diff --git a/electrum/address_synchronizer.py b/electrum/address_synchronizer.py
index 6183f96..1f28c28 100644
--- a/electrum/address_synchronizer.py
+++ b/electrum/address_synchronizer.py
@@ -227,7 +227,7 @@ class AddressSynchronizer(Logger, EventListener):
                 self.unregister_callbacks()
                 self.network = None
 
-    def add_address(self, address):
+    def add_address(self, address: str) -> None:
         if address not in self.db.history:
             self.db.history[address] = []
         if self.synchronizer:
diff --git a/electrum/lnwatcher.py b/electrum/lnwatcher.py
index 14ee275..c86a284 100644
--- a/electrum/lnwatcher.py
+++ b/electrum/lnwatcher.py
@@ -2,7 +2,7 @@
 # Distributed under the MIT software license, see the accompanying
 # file LICENCE or http://www.opensource.org/licenses/mit-license.php
 
-from typing import TYPE_CHECKING, Optional
+from typing import TYPE_CHECKING, Optional, Dict, Callable, Awaitable
 
 from . import util
 from .util import TxMinedInfo, BelowDustLimit, NoDynamicFeeEstimates
@@ -27,11 +27,9 @@ class LNWatcher(Logger, EventListener):
         Logger.__init__(self)
         self.adb = lnworker.wallet.adb
         self.config = lnworker.config
-        self.callbacks = {}  # address -> lambda function
+        self.callbacks = {}  # type: Dict[str, Callable[[], Awaitable[None]]]  # address -> lambda function
         self.network = None
         self.register_callbacks()
-        # status gets populated when we run
-        self.channel_status = {}
         self._pending_force_closes = set()
 
     def start_network(self, network: 'Network'):
@@ -40,18 +38,21 @@ class LNWatcher(Logger, EventListener):
     def stop(self):
         self.unregister_callbacks()
 
-    def get_channel_status(self, outpoint):
-        return self.channel_status.get(outpoint, 'unknown')
-
-    def remove_callback(self, address):
+    def remove_callback(self, address: str) -> None:
         self.callbacks.pop(address, None)
 
-    def add_callback(self, address, callback, *, subscribe=True):
+    def add_callback(
+        self,
+        address: str,
+        callback: Callable[[], Awaitable[None]],
+        *,
+        subscribe: bool = True,
+    ) -> None:
         if subscribe:
             self.adb.add_address(address)
         self.callbacks[address] = callback
 
-    async def trigger_callbacks(self, *, requires_synchronizer=True):
+    async def trigger_callbacks(self, *, requires_synchronizer: bool = True):
         if requires_synchronizer and not self.adb.synchronizer:
             self.logger.info("synchronizer not set yet")
             return
diff --git a/electrum/synchronizer.py b/electrum/synchronizer.py
index 3fbdfcd..696b663 100644
--- a/electrum/synchronizer.py
+++ b/electrum/synchronizer.py
@@ -83,7 +83,7 @@ class SynchronizerBase(NetworkJobOnDefaultServer):
             # we are being cancelled now
             self.session.unsubscribe(self.status_queue)
 
-    def add(self, addr):
+    def add(self, addr: str) -> None:
         if not is_address(addr): raise ValueError(f"invalid bitcoin address {addr}")
         self._adding_addrs.add(addr)  # this lets is_up_to_date already know about addr