Show a warning flash, when creating a part from an info provider that has no category autoprovided

This partially fixes the problems described in discussion #808

Author: jbtronics

src/Controller/PartController.php

@@ -229,6 +229,10 @@ public function createFromInfoProvider(Request $request, string $providerKey, st
         $dto = $infoRetriever->getDetails($providerKey, $providerId);
         $new_part = $infoRetriever->dtoToPart($dto);
 
+        if ($new_part->getCategory() === null || $new_part->getCategory()->getID() === null) {
+            $this->addFlash('warning', t("part.create_from_info_provider.no_category_yet"));
+        }
+
         return $this->renderPartForm('new', $request, $new_part, [
             'info_provider_dto' => $dto,
         ]);

translations/messages.en.xlf

@@ -12257,5 +12257,11 @@ Please note, that you can not impersonate a disabled user. If you try you will g
         <target>Update existing part from info provider</target>
       </segment>
     </unit>
+    <unit id="X5tEZJs" name="part.create_from_info_provider.no_category_yet">
+      <segment>
+        <source>part.create_from_info_provider.no_category_yet</source>
+        <target>Category could not be automatically determined by the info provider. Review the data and select the category manually.</target>
+      </segment>
+    </unit>
   </file>
 </xliff>