Allow tighter integration with `fzf` about 1pass

[maricn]

I hacked away a primitive solution that makes it possible to use 1pass and fzf like this

alias fp='1pass | fzf --preview "1pass --pretty {}" --bind "enter:execute(1pass {})"' 

Shouldn't be too hard to implement ability to have hotkeys for (1) copying username and (2) copying password, without exiting the fzf dialog. 1pass would only need another command to print username in addition to the jq colored output of the .overview field of the item.

But that's a big change of your API, so let me know if you find that useful, I can refactor and push these days...