[0.16] Prevent autocomplete/predictive text on input for wallet import

It's a security risk - when a user types their entire seed phrase, smart keyboards will remember the order of the words and potentially suggest the entire seed phrase to someone who gains malicious access to the keyboard.

To mitigate this, the input needs to be type="password". Then we need to make the text still visible to the user while actually typing into the password input.

There's no better way to do this. Mobile browsers will not necessarily respect the "autocomplete" and "autocorrect" flags. Using a password input is the only way to reliably shut off predictive text.

Edit: We can also try assigning a unique "name" field to the input every time the input is rendered, or try type="new-password"

Weight: 0.16. See related tickets.