UI: Update BC Registries Account login screen

[J-Baese]

Change to: simplified account flow BC reg login screen

• Remove yellow alert box
• Change button to say "Continue with BC Service Card"

figma: https://www.figma.com/design/9geDdDQoe3Hdx8o1ygJ0sw/Simplified-Account-Creation?node-id=8906-2014&t=tGgmxehSPFY3oPqx-1