feat: provide UIs for showing ACF Option Pages in the GraphQL Schema

[jasonbahl]

What does this implement/fix? Explain your changes.

ACF Pro v6.2 introduced a UI for creating ACF Option Pages.

This PR brings support for configuring those option pages to show in GraphQL and set the GraphQL Type Name to represent the options page.

Here's how it works 👇🏻

Configure Options Page

When registering an Options Page via the ACF PRO v6.2+ UI, you can configure the Options Page to show in graphql, and set the GraphQL Type Name.

You will see the data in the columns on the list options page as well:

Assign a Field Group

If you assign an ACF Field Group to the Options Page:

You will be able to see that the ACF Field Group is associated with the Options Page Type

Query the Options

Then you can fill in values for the options page:

And query for the options in GraphQL:

Does this close any currently open issues?

closes #83

Any other comments?

Folks using JSON or PHP to register options pages can still do so as they did before, adding fields graphql_type_name and show_in_graphql:

acf_add_options_page(
	[
		'page_title' => 'OptionsPageNode',
		'menu_title' => __( 'Options Page Node' ),
		'menu_slug'  => 'options-page-node',
		'capability' => 'edit_posts',
		show_in_graphql' => true,
		'graphql_type_name'   => 'OptionsPageNode',
	]
);

[jasonbahl]

Closing this PR as it has some conflicts. I re-worked the code into this PR #88