Feature flags should retain flag state after refresh

[phenixcoder]

When feature flags are initialised, the initialise function should check for existing feature flags and their states and apply saved state on top of passed feature flags.

In case of refresh, the updated feature flags get reset.

[atombrenner]

In my app, feature flags are stored in localStorage. I use your extension to toggle features. If the chrome extension stores the state by itself and overrides the state supplied by the app, my app integration would no longer work.
I suggest, that the app can control this behavior.

[phenixcoder]

When configuring feature flags, We can control this by passing additional attribute to use plugin storage or not use storage at all.

In my case I use this for development and with every refresh, I need to toggle my feature flags again.