Re #8471 - Simplification of CRUD functions- conversion source of private key repository to one file- added comments
Re #8471 - Simplification of CRUD functions- conversion source of certificate repository to one file- added comments
Re #8471 - Modified source- deleted redundat files- deleted '_impl' from repositories filename
Re #8471 - Edited arguments in headers of functions
Re #8471 - Initialization of DAO implementation- created data class according to DB tables (Certificate, PrivateKey)- created abstract class for DB communication