Add more accurate BadRequest handling

- Currently bad requests are getting intercepted by some default method that translates them into 503s. Add explict capture.

Author: KludgeKML

app/controllers/application_controller.rb

@@ -9,6 +9,7 @@ class ApplicationController < ActionController::Base
   rescue_from GdsApi::HTTPNotFound, with: :cacheable_404
   rescue_from GdsApi::InvalidUrl, with: :cacheable_404
   rescue_from GdsApi::HTTPForbidden, with: :error_403
+  rescue_from GdsApi::HTTPBadRequest, with: :error_400
   rescue_from RecordNotFound, with: :cacheable_404
 
   # Because this code contains an if statement evaluated on Rails load and is just
@@ -27,6 +28,10 @@ class ApplicationController < ActionController::Base
 
   helper_method :content_item
 
+  def error_400
+    error :bad_request
+  end
+
   def error_403
     error :forbidden
   end

lib/content_item_loader.rb

@@ -32,7 +32,7 @@ def load_from_sources(base_path)
     end
 
     default_loader.load(base_path:)
-  rescue GdsApi::HTTPErrorResponse, GdsApi::InvalidUrl => e
+  rescue GdsApi::HTTPErrorResponse, GdsApi::InvalidUrl, GdsApi::HTTPBadRequest => e
     e
   end