Swashbuckle generates VersionOptions as object instead of string in Swagger docs

Although the workflow definitiond API endpoint accepts version options in string-format (which gets model-bound to `VersionOptions` ), the swagger documentation displays a complex object input.

See: https://user-images.githubusercontent.com/581644/160803488-f8597fcc-3207-4a59-b89d-1e13ef9388f4.png

Swashbuckle probably supports a way to customize this.

See [this discussion](https://github.com/elsa-workflows/elsa-core/discussions/2902)

Start with the workflow definition API endpoint and the VersionOptions model-binding behavior described in the issue, then review the linked Swashbuckle discussion for the relevant customization point. Done means the Swagger documentation presents version options as a string input rather than a complex object.

Written by the indexing model from the issue text.