[EPIC] Complex Type Support

[andygrove]

What is the problem the feature request solves?

We would like Comet to fully support complex types (arrays, structs, and maps). This issue is for tracking all of the individual issues.

• [ ] https://github.com/apache/datafusion-comet/issues/434
  • [ ] Array
  • [ ] Struct
  • [ ] Map
• Iceberg Parquet Scan
  • [ ] Array
  • [ ] Struct
  • [ ] Map
• Expressions
  • [ ] Array
  • [ ] https://github.com/apache/datafusion-comet/issues/1042
  • [ ] Update to_json to support arrays
  • [ ] Implement CAST from array to string
  • [ ] Struct
  • [x] https://github.com/apache/datafusion-comet/issues/815
  • [x] https://github.com/apache/datafusion-comet/issues/814
  • [ ] https://github.com/apache/datafusion-comet/issues/813
  • [ ] Map
  • [ ] https://github.com/apache/datafusion-comet/issues/1044
  • [ ] Implement CAST from Map to String
  • [ ] Add map support to to_json

Describe the potential solution

No response

Additional context

No response