New wallet wizard loading page

While looking at #3914 I got the impression that the current dialog (especially with the new button there) looks a bit confusing on first sight:

I think the current design could be changed to increase the user experience and add a more natural option to create a new wallet:

A list of recently opened wallets is shown. On the button of that list there are buttons to "extend" the list by either loading a wallet from file or creating a new one.

The user wants to open a wallet without encryption.

After creating "New Wallet", the button disappears, just like in @SomberNight's PR.

In my opinion, this gives the dialog a tidier appearance while still providing more information. The list of recent wallets should help people find the right wallet. The "Last opened" date can be obtained by reading the file modification as closing Electrum seems to save the wallet file.

What do you think? Is this better than what we have now?

The issue provides screenshots and a proposed flow for the wallet-loading dialog, but names no files, tests, or entry points. Start by locating the current wallet-loading dialog in the desktop application and compare it with the described recent-wallet, load-from-file, and create-wallet states. Done means the agreed design is implemented and its dialog behavior is verified.