[FSSDK-10544] Refactor Hooks code + tests

[junaed-optimizely]

Summary

• SDK hooks do not follow the "Rules of Hooks". Specially the one that states "Do not call Hooks after a conditional return statement". Check the - Official React Doc for more detail
• Broken test cases fixed
• clientReady is set to true even though dataReadyPromise returns success == false, bug fixed
• A useEffect's within useDecision will flap the auto update listeners on every render. #196 has been addressed

Test plan

• Hook test suite is modified to fix some broken mocks and tests
• Manual testing

Issues

• FSSDK-10544

[mikechu-optimizely]

LGTM.

No show-stoppers IMHO, but I have some curiosity questions 👇 DM me if it's easier.