Support for union scenario

### Which Data Mapper Version are you using ?

v2

### Describe the Bug with repro steps

The current Data Mapper lacks support for union scenario, where 2 or more repeating input nodes need to be combined into a single repeating node at destination. This is a common requirement for data transformation but is not currently addressed in the tool.

### Screenshots or Videos

Reference to BizTalk mapper: [https://learn.microsoft.com/en-us/biztalk/core/looping-functoid]()

- BizTalk Mapper supported this scenario using the looping functoid, which allowed multiple input records to be merged into a single repeating output structure.
- This ensured that records from different sources could be combined seamlessly while preserving their relationships.

### Version

5\.38.0

### Additional context

*No response*