uploads: remove batch upload page.

* Make /uploads/batch redirect to /uploads/new.
* Remove /uploads/image_proxy.

app/logical/image_proxy.rb

@@ -1,24 +0,0 @@
-# frozen_string_literal: true
-
-class ImageProxy
-  class Error < StandardError; end
-
-  def self.needs_proxy?(url)
-    fake_referer_for(url).present?
-  end
-
-  def self.fake_referer_for(url)
-    Sources::Strategies.find(url).headers["Referer"]
-  end
-
-  def self.get_image(url)
-    raise Error, "URL not present" unless url.present?
-    raise Error, "Proxy not allowed for this url (url=#{url})" unless needs_proxy?(url)
-
-    referer = fake_referer_for(url)
-    response = Danbooru::Http.timeout(30).headers(Referer: referer).get(url)
-    raise Error, "Couldn't proxy image (code=#{response.status}, url=#{url})" unless response.status.success?
-
-    response
-  end
-end

app/logical/sources/strategies/base.rb

@@ -211,12 +211,6 @@ module Sources
         nil
       end
 
-      # Subclasses should merge in any required headers needed to access resources
-      # on the site.
-      def headers
-        {}
-      end
-
       # Download the file at the given url, or at the main image url by default.
       def download_file!(download_url = image_url)
         response, file = http_downloader.download_media(download_url)

app/logical/sources/strategies/moebooru.rb

@@ -100,10 +100,6 @@ module Sources
         tags.map(&:first).flat_map(&method(:translate_tag)).uniq.sort
       end
 
-      def headers
-        { "Referer" => "http://#{site_name}" }
-      end
-
       # Moebooru returns an empty array when doing an md5:<hash> search for a
       # deleted post. Because of this, api_response may be empty in some cases.
       def api_response

app/logical/sources/strategies/pixiv.rb

@@ -177,10 +177,6 @@ module Sources
         api_illust[:description]
       end
 
-      def headers
-        { "Referer" => "https://www.pixiv.net" }
-      end
-
       def normalize_for_source
         return nil if illust_id.blank?
         "https://www.pixiv.net/artworks/#{illust_id}"

app/logical/sources/strategies/weibo.rb

@@ -93,10 +93,6 @@ module Sources
         image_urls.map { |img| img.gsub(%r{.cn/\w+/(\w+)}, '.cn/orj360/\1') }
       end
 
-      def headers
-        { "Referer" => "https://weibo.com" }
-      end
-
       def page_url
         if api_response.present?
           artist_id = api_response["user"]["id"]