Allow Setting the "maxDepth" Option

[gabehayes]

Description of changes: I was running into an error when generating documents appsync and graphql types.

The root of the issue had to do with generating queries when my schema was returning nested types. See this issue for more details.

To address, I added the maxDepth option to fileDetails when generating appsync or graphql types.

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.

[gabehayes]

@adrianhall Can you provide some guidance here? Is this not something you are looking to add to the plugin or is there a better way to approach this that I'm not thinking of?

Happy to help in any way I can.

[bsmith42]

This PR allows the same maxDepth argument to be passed in that is similar to the amplify CLI.

[danb235]

Any news on merging this?