feature requests: Add default profile capability + auto-enter functionality on Yubikey tap

[Gowiem]

@robertoriv digging this workflow now that I got it working correctly, so thank you a ton for creating it!

Two things I'm thinking that would improve this greatly:

1. Default profile. About 90% of the time I type in yfa $MY_DEFAULT_PROFILE and then hit enter. It would be awesome to be able to skip that by just typing yfa and it already knows my default profile so it requires a tap for that. Simple but big usability thing. Not sure how you would select the default profile, but maybe it's an input during install or a setting in the workflow configuration itself?
2. Auto enter on Yubikey tap. After I find my profile, hit enter, and hit my yubikey I finally need to hit enter again to paste the MFA code that was created. The final enter is cumbersome as it seems unnecessary. If we already have the code then ending the workflow and pasting the MFA code immediately seems the fastest possible workflow.

Would appreciate to hear your thoughts. Also if you want to outline how you would implement either of these at a high level then I could potentially take a look at contributing here if I can roll up my rusty python sleeves. Appreciate it @robertoriv!

[Gowiem]

@robertoriv any thoughts on this one?