Pull request type

Please check the type of change your PR introduces:

• Bugfix
• New feature or enhancement
• UI change (please include screenshot!)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Internationalization and localization
• Other (please describe):

What is the current behavior?

Requests for JSON<>CSV conversion in
#200
#671
#708

What is the new behavior?

• Converts a JSON array of objects to a grid view that can be copied to clipboard as CSV/TSV/FSV.
• Flattens nested JSON objects and ignores any nested arrays eg {"a":{"b":1,"c":{"d":2},"e":[3,4]}} becomes {"a_b":1,"a_c_d":2}
• Smart detection triggered by any JSON. Should this be smarter and only detect on JSON arrays?
• Any conversion errors (eg not valid JSON, not a JSON array) show as an error message in a single-cell datagrid, and cannot copy to clipboard (button is disabled)
• Includes GUI and CLI tools.
• Would resolve JSON to Table #708, and half of JSON < > CSV (or Excel) #200

Other information

Possible future ideas:

• Convert TSV/CSV to JSON:
  • Add a 'paste' button to the datagrid to paste TSV/CSV/CSV-French (auto detect or use the setting?) then convert to json
  • Leave datagrid on right hand side but remove 'input'/'output' labels since the datagrid can be input via the paste mechanism
  • This removes complexity of error handling with a toggle between grid view and text view of the TSV/CSV.
  • Would resolve CSV / XML / Excel to JSON #671 and JSON < > CSV (or Excel) #200
• Respond to compact mode, showing as vertical layout.

Quality check

Before creating this PR:

• Did you follow the code style guideline as described in CONTRIBUTING.md
• Did you build the app and test your changes?
• Did you check for accessibility? On Windows, you can use Accessibility Insights for this.
• Did you verify that the change work in Release build configuration
• Did you verify that all unit tests pass
• If necessary and if possible, did you verify your changes on:
  • Windows
  • macOS (DevToys 2.0)
  • Linux (DevToys 2.0)

I couldn't build Release, but also couldn't build Release for the base dev/2.0 branch. Error message is:
Could not write to output file 'C:\Programming\DevToys.v2\obj\AnyCPU\DevToys.Business\Release\net7.0\generated\CommunityToolkit.Mvvm.SourceGenerators\CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator\DevToys.Business.ViewModels.ToolPageViewModel.ToggleSelectedMenuItemFavorite.g.cs' -- 'Could not find a part of the path 'C:\Programming\DevToys.v2\obj\AnyCPU\DevToys.Business\Release\net7.0\generated\CommunityToolkit.Mvvm.SourceGenerators\CommunityToolkit.Mvvm.SourceGenerators.RelayCommandGenerator\DevToys.Business.ViewModels.ToolPageViewModel.ToggleSelectedMenuItemFavorite.g.cs'.' DevToys.Business (net7.0) C:\Programming\DevToys.v2\src\app\dev\DevToys.Business\CSC