cookies

Is your feature request related to a problem? Please describe.

I find that the extension has a significant impact on my eyes when setting grey/whitelists. I could not find any other issue related to this, so I thought it could be something to be considered.

Describe the solution you'd like

Implement a inverted or dark color scheme for the extension UI.

**Describe alternatives y

Describe the bug
I do a yarn install as part of my Dockerfile image building steps and cookies.keys seem to be required.

Error observed:

ode:internal/process/promises:245                                                                                                  
          triggerUncaughtException(err, true /* fromPromise */);                                                  

Now that CookieManager.flush() is added could you also add flush to index.d.ts?