Fix #5363: Inconsistent order of files from zip uploads.

Upload files in natural order rather than archive order when uploading archive files.

Before files were listed in the same order they appeared in the zip file. This could be in
non-alphabetical order, or even with files from different directories interleaved between each
other. Now files are uploaded in natural order, which is alphabetical order but with numbers sorted
properly, so that `file-9.jpg` appears before `file-10.jpg`.

app/models/upload.rb

@@ -206,7 +206,7 @@ class Upload < ApplicationRecord
         tmpdir, filenames = file.extract!
         tmpdirs << tmpdir
 
-        filenames.map do |filename|
+        Danbooru.natural_sort(filenames).map do |filename|
           name = "file://#{original_filename}/#{Pathname.new(filename).relative_path_from(tmpdir)}" # "file://foo.zip/foo/1.jpg"
           UploadMediaAsset.new(upload: self, file: filename, source_url: name)
         end