refactor: Replace Static Methods in MPNotificationController and MPStateMachine

[nickolas-dimitrakas]

Background

• The static methods in MPNotificationController and MPStateMachine made it difficult to mock or test functionality related to push notification handling. This also created tight coupling between components and limited flexibility when integrating with other parts of the SDK.

What Has Changed

• Replaced static methods in MPNotificationController and MPStateMachine with instance methods.
• Updated references throughout the codebase to use the appropriate instance accessors instead of static calls.

Screenshots/Video

• N/A

Checklist

• I have performed a self-review of my own code.
• I have made corresponding changes to the documentation.
• I have added tests that prove my fix is effective or that my feature works.
• I have tested this locally.

Additional Notes

• I have chosen the base branch as the branch that I will add more unit tests on.

Reference Issue (For employees only. Ignore if you are an outside contributor)

• Closes https://rokt.atlassian.net/browse/SDKE-430