feat: add reset()

[timebis]

This pull request introduces a new Reset method to both the MovingAverage and ConcurrentMovingAverage classes and adds corresponding unit tests to ensure the functionality works as expected.

Key changes include:

• New Reset Method:

  • ma.go: Added a Reset method to the MovingAverage class to reset its internal state.
  • ma_concurrent.go: Added a Reset method to the ConcurrentMovingAverage class, ensuring thread safety by locking and unlocking the mutex.

• Unit Tests:

  • ma_test.go: Added a new test function TestReset to verify the behavior of the Reset method, including checking the count, average, and values before and after resetting.