[split] Move extract plugin to oh-my-fish/plugin-extract

https://github.com/oh-my-fish/plugin-extract

plugins/extract/extract.fish

-# Taken from: https://github.com/dideler/dotfiles/blob/master/functions/extract.fish
-
-function extract --description "Expand or extract bundled & compressed files"
-  set --local ext (echo $argv[1] | awk -F. '{print $NF}')
-  switch $ext
-    case tar  # non-compressed, just bundled
-      tar -xvf $argv[1]
-    case gz
-      if test (echo $argv[1] | awk -F. '{print $(NF-1)}') = tar  # tar bundle compressed with gzip
-        tar -zxvf $argv[1]
-      else  # single gzip
-        gunzip $argv[1]
-      end
-    case tgz  # same as tar.gz
-      tar -zxvf $argv[1]
-    case bz2  # tar compressed with bzip2
-      tar -jxvf $argv[1]
-    case rar
-      unrar x $argv[1]
-    case zip
-      unzip $argv[1]
-    case '*'
-      echo "unknown extension"
-  end
-end