Make parent parameter object optional if all fields are optional

[dolencd]

When a specification defines some parameters, such as:

{
  "name": "id",
  "in": "path",
  "required": true,
  "type": "string"
},
{
  "name": "accept-language",
  "in": "header",
  "required": false,
  "type": "string"
}

The current output contains:

parameters: {
    path: {
      id: string;
    };
    header: {
      "accept-language"?: string;
    };
};

Maybe this would be a good option rather than the default behaviour, but I'd like the header key in this example to be optional. This makes sense since all the fields included in it are optional and you may want to include none of them.

[drwpow]

This makes sense, and I’d argue this is expected behavior, because it means most requests likely happen without specifying those headers at all.

I don’t think this scenario would apply to all situations where this happens, but here in headers I think it’s a good improvement.

Would love a PR fixing this if someone has time.

[drwpow]

Update: this has been added in #968 and will ship with the next v6 release.