Cover list of controllers and handlers with tests

[Oleh-Kril]

Description

1. Write integration tests for the following endpoints in the listed controllers.
2. Write unit tests for the corresponding handlers.
3. Identify and fix any issues flagged by SonarQube rules within the provided directories.

EmailController

1. POST / - Send

StatisticRecordController

1. GET / - GetAll
2. GET /{id:int} - GetByQrId
3. GET /{id:int} - ExistByQrId
4. GET /{id:int} - GetAllByStreetcodeId
5. POST / - Create
6. PUT /{id:int} - Update
7. DELETE /{id:int} - Delete

InstagramController

1. GET / - GetAll

UsersController

1. GET /api/Users/GetByUserName - GetByUserName
2. GET /api/Users/GetOtherUserByUserName/{userName} - GetOtherUserByUserName
3. PUT /api/Users/Update - Update
4. DELETE /api/Users/Delete/{email} - Delete
5. POST /api/Users/ForgotPassword - ForgotPassword
6. POST /api/Users/UpdateForgotPassword - UpdateForgotPassword

ExpertisesController

1. GET / - GetAll