Extend #parse to accept a suggestions_filter_enabled param

This will allow the front end to specify the behavior as needed.

app/services/preview_markdown_service.rb

@@ -38,7 +38,9 @@ class PreviewMarkdownService < BaseService
                                           head_sha: params[:head_sha],
                                           start_sha: params[:start_sha])
 
-    Gitlab::Diff::SuggestionsParser.parse(text, position: position, project: project)
+    Gitlab::Diff::SuggestionsParser.parse(text, position: position,
+                                                project: project,
+                                                supports_suggestion: params[:preview_suggestions])
   end
 
   def preview_sugestions?

lib/gitlab/diff/suggestions_parser.rb

@@ -10,10 +10,12 @@ module Gitlab
         # Returns an array of Gitlab::Diff::Suggestion which represents each
         # suggestion in the given text.
         #
-        def parse(text, position:, project:)
+        def parse(text, position:, project:, supports_suggestion: true)
           return [] unless position.complete?
 
-          html = Banzai.render(text, project: nil, no_original_data: true)
+          html = Banzai.render(text, project: nil,
+                                     no_original_data: true,
+                                     suggestions_filter_enabled: supports_suggestion)
           doc = Nokogiri::HTML(html)
           suggestion_nodes = doc.search('pre.suggestion')