Login should have username and password on same screen

### Description

When logging into FlowForge Cloud I go thru the following:
1. I am promoted for username, press Login button, and
2. then I am promoted for password, press login button again

I think having the username and password on the same screen would be a much better user experience. Also makes better use of password managers and requires just one button click.

### Epic/Story

_No response_

### Have you provided an initial effort estimate for this issue?

I have provided an initial effort estimate