### What problem does this PR solve?
Feat: The query variable of a loop operator can be a nested array
variable. #10866
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Feat: Modify the style of the query variable dropdown list. #10866
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
### What problem does this PR solve?
Feat: The query variables of the subsequent operators can reference the
structured variables defined in the agent operator. #10866
### Type of change
- [x] New Feature (non-breaking change which adds functionality)
