[FSSDK-10120] setForcedDecision does not reflects in Optimizely client instance

[junaed-optimizely]

Summary

• [BUG] setForcedDecision does not work after update to version 3.0.1 #256 has been addressed
• user context reset for the same user bug fix for decision methods
• Performance improvment for user prop check

Test plan

• As we are mocking the inner client, there is no way to add test cases for this specific use case right now. However there is a dedicated ticket FSSDK-10439 to improve the "Optimizely client" test coverage. Improvement should be expected from there.

Issues

FSSDK-10120

[mikechu-optimizely]

LGTM as our per our collab DMs