Fix escaping for video filenames

src/invidious.cr

@@ -4002,7 +4002,8 @@ get "/videoplayback" do |env|
     env.response.status_code = response.status_code
 
     if title = env.params.query["title"]?
-      env.response.headers["Content-Disposition"] = "attachment; filename=\"#{title}\""
+      # https://blog.fastmail.com/2011/06/24/download-non-english-filenames/
+      env.response.headers["Content-Disposition"] = "attachment; filename=\"#{URI.escape(title)}\"; filename*=UTF-8''#{URI.escape(title)}"
     end
 
     response.headers.each do |key, value|

src/invidious/views/watch.ecr

@@ -59,17 +59,17 @@
                     <label for="download_widget"><%= translate(locale, "Download as: ") %></label>
                     <select style="width:100%" name="download_widget" id="download_widget">
                     <% video_streams.each do |option| %>
-                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= HTML.escape(video.title) %>-<%= video.id %>.mp4"}'>
+                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= URI.escape(video.title) %>-<%= video.id %>.mp4"}'>
                             <%= option["quality_label"] %> - <%= option["type"].split(";")[0] %> @ <%= option["fps"] %>fps - video only
                         </option>
                     <% end %>
                     <% audio_streams.each do |option| %>
-                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= HTML.escape(video.title) %>-<%= video.id %>.mp4"}'>
+                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= URI.escape(video.title) %>-<%= video.id %>.mp4"}'>
                             <%= option["type"].split(";")[0] %> @ <%= option["bitrate"] %>k - audio only
                         </option>
                     <% end %>
                     <% fmt_stream.each do |option| %>
-                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= HTML.escape(video.title) %>-<%= video.id %>.mp4"}'>
+                        <option value='{"id":"<%= video.id %>","itag":"<%= option["itag"] %>","title":"<%= URI.escape(video.title) %>-<%= video.id %>.mp4"}'>
                             <%= itag_to_metadata?(option["itag"]).try &.["height"]? || "~240" %>p - <%= option["type"].split(";")[0] %>
                         </option>
                     <% end %>