Import - richTextV2 import (#12868)

- Enable markdown import
- Decrease the createMany batch size on import

packages/twenty-server/src/engine/core-modules/record-transformer/services/record-input-transformer.service.ts

@@ -99,13 +99,13 @@ export class RecordInputTransformerService {
     let convertedMarkdown: string | null = null;
 
     try {
-      convertedMarkdown = parsedValue.blocknote
+      convertedMarkdown = isDefined(parsedValue.blocknote)
         ? await serverBlockNoteEditor.blocksToMarkdownLossy(
             JSON.parse(parsedValue.blocknote),
           )
         : null;
     } catch {
-      convertedMarkdown = parsedValue.blocknote;
+      convertedMarkdown = parsedValue.blocknote || null;
     }
 
     const convertedBlocknote = parsedValue.markdown