Adds public function for setting info object directly

[irvinesunday]

Fixes #3446

By adding support for extending namespace, we will be able to add extensions to the OpenAPI info object via the new function - setNamespaceExtension(...)

[timotheeguerin]

I don't think setNamrspaceextension is the correct name setExyensiom already able to be applied to a namespace. The problem here is that we don't have a type that map to info.

[irvinesunday]

@timotheeguerin your committed suggested change has broken build:

export function setInfo(
  program: Program,
  entity: Namespace,
  data: AdditionalInfo & Record<ExtensionKey, unknown>
) { }

[irvinesunday]

@timotheeguerin thanks a bunch for your input here 🙏🏾
When do you think the next release will be going out?