feat: Adding Steam Guard using QR code

[uaevuon]

Feature description

Select STEAM instead of TOTP automatically when adding Steam Guard with QR code.

Motivation

I can generate QR code by using steamguard-cli. But if I use this QR to add steam on 2fas, it goes wrong.
2FAS selects TOTP instead of STEAM, so it generate 6 digits, not 5 letters.

Acknowledgements

• This issue is not a duplicate of an existing feature request.
• I have chosen an appropriate title.
• All requested information has been provided properly.