1332 refactor fusedapi
Description
FusedApiImpl is refactored in order to increase maintainability and more testable. FusedApi interface is introduced which is implemented by FusedApiImpl. Now Dependent class of FusedApiImpl depends on abstraction instead of concrete implementation.
Some unit test was being failed because of updating the package structure. FusedApiImplTest and AppInstallProcessorTest are fixed now.