[MM-13840] Change eMail as a post-verification action (#10253)

* Change eMail as a post-verification action

* Fix broken test

* comment for special behavior, tests

* govet

* Check for already existent eMails when require email verification is turned on before accepting update

api4/websocket_test.go

@@ -304,12 +304,12 @@ func TestWebSocketStatuses(t *testing.T) {
 	user := model.User{Email: strings.ToLower(model.NewId()) + "success+test@simulator.amazonses.com", Nickname: "Corey Hulen", Password: "passwd1"}
 	ruser := Client.Must(Client.CreateUser(&user)).(*model.User)
 	th.LinkUserToTeam(ruser, rteam)
-	store.Must(th.App.Srv.Store.User().VerifyEmail(ruser.Id))
+	store.Must(th.App.Srv.Store.User().VerifyEmail(ruser.Id, ruser.Email))
 
 	user2 := model.User{Email: strings.ToLower(model.NewId()) + "success+test@simulator.amazonses.com", Nickname: "Corey Hulen", Password: "passwd1"}
 	ruser2 := Client.Must(Client.CreateUser(&user2)).(*model.User)
 	th.LinkUserToTeam(ruser2, rteam)
-	store.Must(th.App.Srv.Store.User().VerifyEmail(ruser2.Id))
+	store.Must(th.App.Srv.Store.User().VerifyEmail(ruser2.Id, ruser2.Email))
 
 	Client.Login(user.Email, user.Password)