[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

store/sqlstore/user_store.go

@@ -1025,9 +1025,10 @@ func (us SqlUserStore) GetForLogin(loginId string, allowSignInWithUsername, allo
 	})
 }
 
-func (us SqlUserStore) VerifyEmail(userId string) store.StoreChannel {
+func (us SqlUserStore) VerifyEmail(userId, email string) store.StoreChannel {
 	return store.Do(func(result *store.StoreResult) {
-		if _, err := us.GetMaster().Exec("UPDATE Users SET EmailVerified = true WHERE Id = :UserId", map[string]interface{}{"UserId": userId}); err != nil {
+		curTime := model.GetMillis()
+		if _, err := us.GetMaster().Exec("UPDATE Users SET Email = :email, EmailVerified = true, UpdateAt = :Time WHERE Id = :UserId", map[string]interface{}{"email": email, "Time": curTime, "UserId": userId}); err != nil {
 			result.Err = model.NewAppError("SqlUserStore.VerifyEmail", "store.sql_user.verify_email.app_error", nil, "userId="+userId+", "+err.Error(), http.StatusInternalServerError)
 		}
 

store/store.go

@@ -259,7 +259,7 @@ type UserStore interface {
 	GetAllUsingAuthService(authService string) StoreChannel
 	GetByUsername(username string) StoreChannel
 	GetForLogin(loginId string, allowSignInWithUsername, allowSignInWithEmail bool) StoreChannel
-	VerifyEmail(userId string) StoreChannel
+	VerifyEmail(userId, email string) StoreChannel
 	GetEtagForAllProfiles() StoreChannel
 	GetEtagForProfiles(teamId string) StoreChannel
 	UpdateFailedPasswordAttempts(userId string, attempts int) StoreChannel

store/storetest/mocks/UserStore.go

@@ -833,13 +833,13 @@ func (_m *UserStore) UpdateUpdateAt(userId string) store.StoreChannel {
 	return r0
 }
 
-// VerifyEmail provides a mock function with given fields: userId
-func (_m *UserStore) VerifyEmail(userId string) store.StoreChannel {
-	ret := _m.Called(userId)
+// VerifyEmail provides a mock function with given fields: userId, email
+func (_m *UserStore) VerifyEmail(userId string, email string) store.StoreChannel {
+	ret := _m.Called(userId, email)
 
 	var r0 store.StoreChannel
-	if rf, ok := ret.Get(0).(func(string) store.StoreChannel); ok {
-		r0 = rf(userId)
+	if rf, ok := ret.Get(0).(func(string, string) store.StoreChannel); ok {
+		r0 = rf(userId, email)
 	} else {
 		if ret.Get(0) != nil {
 			r0 = ret.Get(0).(store.StoreChannel)