Add Moodle data source integration (#11325)

### What problem does this PR solve?

This PR adds a native Moodle connector to sync content (courses,
resources, forums, assignments, pages, books) into RAGFlow.

### Type of change

- [x] New Feature (non-breaking change which adds functionality)

---------

Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>

common/data_source/__init__.py

@@ -14,6 +14,7 @@ from .google_drive.connector import GoogleDriveConnector
 from .jira.connector import JiraConnector
 from .sharepoint_connector import SharePointConnector
 from .teams_connector import TeamsConnector
+from .moodle_connector import MoodleConnector
 from .config import BlobType, DocumentSource
 from .models import Document, TextSection, ImageSection, BasicExpertInfo
 from .exceptions import (
@@ -36,6 +37,7 @@ __all__ = [
     "JiraConnector",
     "SharePointConnector",
     "TeamsConnector",
+    "MoodleConnector",
     "BlobType",
     "DocumentSource",
     "Document",