title: Convert Maybe<string>[]' to 'string[]
body: <p>I am using graphql with generated types and struggling with how to convert them to the type I need to pass it to my data service calls.</p>
  <p>@graphql-codegen has given me an args type of</p>
  <pre><code>export type QueryOrdersArgs = {
    ids: Array&lt;Maybe&lt;Scalars['ID']&gt;&gt;;
  };
  </code></pre>
  <p>(I don't really understand why its generated as a Maybe type, as the graphql schema enforces that I only query with a parameter of an array of ids (strings))</p>
  <p>In my resolver, I need to call into a service which takes an array of strings.  Everything works as expected (with @ts-ignore) but now I need to fix up my types.</p>
  <pre><code>const { orderIds } = args;
  const result = getOrder(orderIds);
  </code></pre>
  <p>I have a codesandbox with just the types here <a href="https://codesandbox.io/s/typescript-playground-export-forked-3fpx9?file=/index.ts" rel="nofollow noreferrer">https://codesandbox.io/s/typescript-playground-export-forked-3fpx9?file=/index.ts</a></p>
  <pre><code>export type Maybe&lt;T&gt; = T | null;
  export type Scalars = {
    ID: string;
    String: string;
    Boolean: boolean;
    Int: number;
    Float: number;
    _FieldSet: any;
  };
  
  let ids: Array&lt;Maybe&lt;Scalars[&quot;ID&quot;]&gt;&gt;;
  
  export const getOrders = (orderIds: Array&lt;string&gt;) =&gt; {
    orderIds.map((x) =&gt; console.log(x));
  };
  
  getOrders(ids);
  </code></pre>
  <p>I currently get the error - &quot;TS2345: Argument of type 'Maybe[]' is not assignable to parameter of type 'string[]'.&quot;</p>
  <p>Any help greatly appreciated</p>