Request: hlsearch highlight in opened results

I'm loving this plugin, thanks for all your hard work on it. But, I wish there was a better highlight option. I have this set:

```vim
let g:ctrlsf_selected_line_hl = 'op'
```

However, the `p` flag only highlights one whole line in the opened result buffer. If there are other results in the same file, they are not highlighted. The highlight color is different from the `Search` highlight for my colorscheme. Also, I cannot go to other results in the file with vim's `n` and `N` commands.

Ack-vim's `let g:ackhighlight=1` would allow me to do that. Can it be done in this plugin too? For reference, I think this is how ack-vim does it:

https://github.com/mileszs/ack.vim/blob/36e40f9ec91bdbf6f1adf408522a73a6925c3042/autoload/ack.vim#L152-L159