feature: add conflict git status to picker

[wvffle]

Did you check the docs?

• I have read all the snacks.nvim docs

Is your feature request related to a problem? Please describe.

Reading through picker documentation, I saw that conflict git status icon is missing.

In Neotree I could have had files with conflicts marked with an icon and a highlight.

Describe the solution you'd like

Add a conflict git status icon and highlight

Describe alternatives you've considered

none

Additional context

No response