[PATCH] Allow alternatives to dmenu for passmenu

[Jan Christian Grünhage]

> So at that point are we to just parameterize everything? Might as well
> write a new script then, right? [...] If you have better ideas on how
> to handle this, I'm all ears.

As a pass user on sway, I'd like to give my input here: To make sure
that the password stays in the clipboard long enough, the actual copying
should be executed with `swaymsg exec`. To achieve that, pulled the
password listing out of `passmenu` into a separate script called
`passlist`, which I then pipe into a fuzzy finder, and then I pipe the
result of that into `xargs swaymsg exec pass -- -c`.

Splitting up the scripts into smaller scripts which then call each other
instead of having "big" scripts like `passmenu` makes it easier for
users to do customization like I did there. `passmenu` is not really all
that long, but it does a few different things, so for the sake of "doing
one thing and doing it well", smaller scripts might be helpful here.

I'm not especially well versed in shell scripting, so maybe I'm
overlooking something here, but for me, this approach has worked well.
If you want patches for that, I can try to do these refactorings at some
point, but the following weeks will sadly still be quite busy for me, so
I'd have to push that out to July.

JC