🐛 Fix null text crash on paste in text editor

The splitTextIntoTextBlocks function in @penpot/draft-js called
.split() on the text parameter without a null check. When pasting
content without text data (e.g., images only), Draft.js passes null
to handlePastedText, causing a TypeError.

Signed-off-by: Andrey Antukh <niwi@niwi.nz>

frontend/packages/draft-js/index.js

@@ -366,6 +366,9 @@ export function getInlineStyle(state, blockKey, offset) {
 const NEWLINE_REGEX = /\r\n?|\n/g;
 
 function splitTextIntoTextBlocks(text) {
+  if (text == null) {
+    return [];
+  }
   return text.split(NEWLINE_REGEX);
 }