* swiper.el: make line numbers consistent with display-line-numbers-mode

[mitch-kyle]

These changes are what came from me investigating how to change
the appearance of the swiper line numbers. This change should add
some customization support for swiper line numbers using the builtin
display-line-numbers-mode as "sane default"

Three changes were made:

1. The line numbers are now right justified.
   see: swiper--candidates

2. The line numbers now have custom faces based on the builtin
   line-number and line-number-current-line faces.
   see: swiper-line-number-face
swiper-current-line-number-face

3. The current line number is highlighted. using an ivy format
   function.
   see: swiper--format-function

[basil-conto]

Thanks, see some of my initial comments after a quick look through the code.

[basil-conto]

LGTM apart from some minor nits/questions.

I'm not sure if this change is small enough to be merged without a copyright assignment, though. Do you already have one on file with the FSF? If not, would you be willing to? If you're not familiar with it, there's some more information at (info "(emacs) Copyright Assignment").

[mitch-kyle]

LGTM apart from some minor nits/questions.

I'm not sure if this change is small enough to be merged without a copyright assignment, though. Do you already have one on file with the FSF? If not, would you be willing to? If you're not familiar with it, there's some more information at (info "(emacs) Copyright Assignment").

I don't but I'm willing to. I'll let you know when the paperwork goes through