### What problem does this PR solve?
feat: catch errors when sending messages #918
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
feat: add OperateDropdown
feat: send debug message #918
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
feat: add FlowHeader and delete edge #918
### Type of change
- [x] New Feature (non-breaking change which adds functionality)