Clean-up of the code path that reports what "git fetch" did to each
ref.
* ps/fetch-ref-update-reporting:
fetch: centralize printing of reference updates
fetch: centralize logic to print remote URL
fetch: centralize handling of per-reference format
fetch: pass the full local reference name to `format_display`
fetch: move output format into `display_state`
fetch: move reference width calculation into `display_state`