Improve KeyChain UI/UX

[Avvrik]

This task is aimed at KeyChain macOS interface. The windows need to be redesigned for a more intuitive and attractive interface with regard to the end users of the app - not for the developers.

The result of this task should be:

1. A "create key" window which is shown to a user when he/she initiates KeyChain either from another service or directly.

2. A "restore key" window in which a user can send a request to restore his/her keys.

3. History of transactions (transaction log) displayed in KeyManager.