D3639: remotenames: add paths argument to remotenames revset

[Yuya Nishihara]

>   > > + at revsetpredicate('remotenames([path, ...])')
>   >
>   > My proposal was `remotenames([pattern])`, just like bookmark(), tag(),
>   >  branch(), etc.
>   >  If we want a convenient way to specify path prefix, we can
>   >  add it to the stringmatcher (e.g. 'remotenames("path:server2")'.)
>   
>   
>   No, I don't want to specify a path prefix. remotenames() will take a path only. Do you want to say that we should allow passing full remotenames instead of just path?

Yes, because a remote branch is merely a branch pulled from peer for example,
and we'll probably want to select it by -r remotebranch("foo/bar") just like
-r branch("foo/bar") for normal branches. Do I get it wrong? Why is it so
important to filter by a peer path, not by a branch name itself?