Add Format Support

### Background
Currently, the `web-csv-toolbox` project supports CSV parsing.
This issue proposes the addition of CSV formatting capabilities to enhance the toolbox's functionality.

### Objective
Implement functionality to format data structures (like JSON) into CSV format, complementing the existing parsing features.

### Requirements
- The formatting function should seamlessly integrate with the current parsing capabilities.
- Performance and efficiency should be considered.
- Adherence to standard CSV formatting conventions is essential.

Start by reviewing the existing CSV parsing implementation and how its public API is exposed. Define the formatting API and supported input data structures before implementing it, then verify standard CSV conventions, integration with parsing capabilities, and performance expectations.

Written by the indexing model from the issue text.