Tests for core functionality

[GoodforGod]

Some tests need to be implemented for all mappers, to check that all mapping options are correct for further regression testing.

• Complex class with all possible fields used in test for each mapper.
• Tests for ClassFactory
• Tests for GenFactoryProvider
• Tests for PsiJavaFileScanner

[GoodforGod]

Difficult to emulate action file behavior, setup is ready but not sure if it is possible to emulate what I expect, have issue with "file read is not possible" something like this

[GoodforGod]

Tests will be planned for 1.1.0 if possible to emulate action behavior and perform proper Integration testing