feat: add function to convert pil image to base64

src/pdf_utils/image_utlis.py

@@ -0,0 +1,9 @@
+from PIL import Image
+import base64
+import io
+
+def pil_image_to_base64(pil_image: Image):
+    buffered = io.BytesIO()
+    pil_image.save(buffered, format="png")
+    img_str = base64.b64encode(buffered.getvalue())
+    return img_str.decode("utf-8")