### What problem does this PR solve?
_Briefly describe what this PR aims to solve. Include background context
that will help reviewers understand the purpose of the PR._
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
- Update sync data source to handle metadata properly
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Co-authored-by: Kevin Hu <kevinhu.sh@gmail.com>
### What problem does this PR solve?
This PR adds webdav storage as data source for data sync service.
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### 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>
### What problem does this PR solve?
```
admin> show version;
show_version
+-----------------------+
| version |
+-----------------------+
| v0.21.0-241-gc6cf58d5 |
+-----------------------+
admin> \q
Goodbye!
```
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
1. Move EMBEDDING_CFG to common.globals
2. Fix error imports
3. Move signal handles to common/signal_utils.py
### Type of change
- [x] Refactoring
---------
Signed-off-by: Jin Hai <haijin.chn@gmail.com>
### What problem does this PR solve?
Refine Confluence connector.
#10953
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
- [x] Refactoring
### What problem does this PR solve?
1. Rename identifier name
2. Fix some return statement
3. Fix some typos
### Type of change
- [x] Refactoring
Signed-off-by: Jin Hai <haijin.chn@gmail.com>