DialectProvider: separate NotificationCenterButton from internal providers and wallet managment 

As a external developer I just want to render `NotificationCenter` in fullscreen, sidebar without `NotificationCenterButton`.

<img width="894" alt="Screenshot 2022-02-12 at 22 03 23" src="https://user-images.githubusercontent.com/2504771/153724719-921141db-3607-4add-9688-ef57c792765b.png">

Made a PR with a proposal — https://github.com/dialectlabs/react/pull/15 