Use module names as the module ident.

Some clients will reuse query windows as the client thinks its just a
nick change if you have a existing query window with a module and a different one messages you.

Fix that by using the modules name as the ident.

Update tests to match new modules ident.

test/IRCSockTest.cpp

@@ -211,7 +211,7 @@ TEST_F(IRCSockTest, OnErrorMessage) {
     EXPECT_THAT(
         m_pTestClient->vsLines,
         ElementsAre(
-            ":*status!znc@znc.in PRIVMSG me :Error from server: foo bar"));
+            ":*status!status@znc.in PRIVMSG me :Error from server: foo bar"));
 }
 
 TEST_F(IRCSockTest, OnInviteMessage) {