🐛 Check for pdf extension

This commit will add a check for the file set's extension (label)
instead of solely relying on the mime type. This will allow us to know
if it's a PDF (as best as we can anyway) even if CharacterizeJob did not
run.

Also, downgraded the version of simple_form because it was causing
crashes in development.

Gemfile.lock

@@ -1035,7 +1035,7 @@ GEM
       faraday (>= 0.17.5, < 3.a)
       jwt (>= 1.5, < 3.0)
       multi_json (~> 1.10)
-    simple_form (5.3.0)
+    simple_form (5.1.0)
       actionpack (>= 5.2)
       activemodel (>= 5.2)
     simplecov (0.16.1)

app/helpers/pdf_js_helper.rb

@@ -3,13 +3,13 @@
 module PdfJsHelper
   def pdf_js_url(file_set_presenter)
     # assumes that the download path exists if the file set has been characterized
-    path = if file_set_presenter.mime_type
-             hyrax.download_path(file_set_presenter.id)
-           else
-             file_set_presenter.solr_document["import_url_ssim"].first
-           end
+    url = if file_set_presenter.mime_type
+            "/pdf.js/web/viewer.html?file=#{hyrax.download_path(file_set_presenter.id)}"
+          else
+            file_set_presenter.solr_document["import_url_ssim"].first
+          end
 
-    "/pdf.js/web/viewer.html?file=#{path}##{query_param}"
+    url + "##{query_param}"
   end
 
   def pdf_file_set_presenter(presenter)
@@ -22,14 +22,19 @@ def pdf_file_set_presenter(presenter)
   end
 
   def first_file_set_pdf(presenter)
-    pdf_file_set_presenters = presenter.file_set_presenters.select(&:pdf?)
-    reader, archival = pdf_file_set_presenters.partition do |fsp|
+    reader, archival = pdf_file_set_presenters(presenter.file_set_presenters).partition do |fsp|
       fsp.solr_document["import_url_ssim"]&.first&.include? "READER"
     end
 
     reader.first || archival.first
   end
 
+  def pdf_file_set_presenters(presenters)
+    presenters.select(&:pdf?) || presenters.select do |file_set_presenter|
+      file_set_presenter.solr_document["label_ssi"].downcase.end_with? ".pdf"
+    end
+  end
+
   def representative_presenter(presenter)
     presenter.file_set_presenters.find { |file_set_presenter| file_set_presenter.id == presenter.representative_id }
   end