Use FileManager in NMockLogger functionalities

[AbolfaZlRezaEe]

What's the problem or feature?

We wrote a manager that we call it FileManager in the application. this class is responsible for managing all functionalities related to files. in NMockLogger, we wrote all functionalities in a custom way.

For the solution we want to

For better code style and good architecture, it's better to use FileManager also for NMockLogger.

Works we should do during this task

• Implement FileManager functionalities instead of custom way.
• Test the result and be sure that it works

[AbolfaZlRezaEe]

Committed to Develop branch.