wtclient+lnrpc: move RemoveTower to Manager

Simiarly to the previous commit, this commit moves the RemoveTower
method from the Client to the TowerClientManager interface. The manager
handles any DB related handling. The manager will first attempt to
remove the tower from the in-memory state of each client and then will
attempt to remove the tower from the DB. If the removal from the DB
fails, the manager will re-add the tower to the in-memory state of each
client.

watchtower/wtclient/client_test.go

@@ -766,7 +766,7 @@ func (h *testHarness) addTower(addr *lnwire.NetAddress) {
 func (h *testHarness) removeTower(pubKey *btcec.PublicKey, addr net.Addr) {
 	h.t.Helper()
 
-	err := h.client.RemoveTower(pubKey, addr)
+	err := h.clientMgr.RemoveTower(pubKey, addr)
 	require.NoError(h.t, err)
 }
 
@@ -1718,7 +1718,7 @@ var clientTests = []clientTest{
 			require.NoError(h.t, err)
 
 			// Remove the old tower address from the client.
-			err = h.client.RemoveTower(
+			err = h.clientMgr.RemoveTower(
 				towerAddr.IdentityKey, oldAddr,
 			)
 			require.NoError(h.t, err)
@@ -1752,7 +1752,7 @@ var clientTests = []clientTest{
 			// negotiation with the server will be in progress, so
 			// the client should be able to remove the server.
 			err := wait.NoError(func() error {
-				return h.client.RemoveTower(
+				return h.clientMgr.RemoveTower(
 					h.server.addr.IdentityKey, nil,
 				)
 			}, waitTime)
@@ -1807,7 +1807,7 @@ var clientTests = []clientTest{
 			// address currently being locked for session
 			// negotiation.
 			err = wait.Predicate(func() bool {
-				err = h.client.RemoveTower(
+				err = h.clientMgr.RemoveTower(
 					h.server.addr.IdentityKey,
 					h.server.addr.Address,
 				)
@@ -1818,7 +1818,7 @@ var clientTests = []clientTest{
 			// Assert that the second address can be removed since
 			// it is not being used for session negotiation.
 			err = wait.NoError(func() error {
-				return h.client.RemoveTower(
+				return h.clientMgr.RemoveTower(
 					h.server.addr.IdentityKey, towerTCPAddr,
 				)
 			}, waitTime)
@@ -1830,7 +1830,7 @@ var clientTests = []clientTest{
 			// Assert that the client can now remove the first
 			// address.
 			err = wait.NoError(func() error {
-				return h.client.RemoveTower(
+				return h.clientMgr.RemoveTower(
 					h.server.addr.IdentityKey, nil,
 				)
 			}, waitTime)
@@ -2223,7 +2223,7 @@ var clientTests = []clientTest{
 
 			// Now we can remove the old one.
 			err := wait.Predicate(func() bool {
-				err := h.client.RemoveTower(
+				err := h.clientMgr.RemoveTower(
 					h.server.addr.IdentityKey, nil,
 				)
 
@@ -2309,7 +2309,7 @@ var clientTests = []clientTest{
 			require.NoError(h.t, err)
 
 			// Now remove the tower.
-			err = h.client.RemoveTower(
+			err = h.clientMgr.RemoveTower(
 				h.server.addr.IdentityKey, nil,
 			)
 			require.NoError(h.t, err)
@@ -2400,7 +2400,7 @@ var clientTests = []clientTest{
 			h.startClient()
 
 			// Now remove the tower.
-			err = h.client.RemoveTower(
+			err = h.clientMgr.RemoveTower(
 				h.server.addr.IdentityKey, nil,
 			)
 			require.NoError(h.t, err)