Add 'Clear all transactions' button to Desktop wallet

[beam-mw]

We have this on mobile and it is very useful in certain cases. Let's add it in Desktop wallets as well.

Also we should consider maybe using the word 'Clear' instead of delete?

[dariatarakanova]

1) Add "Clear local wallet data" to General settings https://zpl.io/aXA0vLE

2) Popup with choice https://zpl.io/b6dqLDW

3) Confirmation https://zpl.io/aRJZeXN

4) Password https://zpl.io/VKZre6R