Migrate playgrounds to GraphiQL

[kirkbyo]

Closes #1367

This PR migrates the default Playground to GraphiQL since graphql-playground is being deprecated.

How I tested this PR:

• Ran the dataloader example to ensure that queries were still functioning.
• Ran the chat example to ensure that mutations + WS subscriptions were still functioning.

[coveralls]

Coverage increased (+0.06%) to 70.746% when pulling db00b2f on kirkbyo:graphiql-playground into 27a2b21 on 99designs:master.

[LouisAldorio]

Well, Graphql Playground is better than this GraphiQl stuff, It is better to stay in GraphQl Playground.

GraphQL Playground uses components of GraphiQL under the hood but is meant as a more powerful GraphQL IDE enabling better (local) development workflows. Compared to GraphiQL, the GraphQL Playground ships with the following additional features: Interactive, multi-column schema documentation.

[giautm]

Another thing is GraphQL Playground support multi-tabs

[Jonsy13]

We had our subscriptions created based on v0.14.0, After upgrading to v0.15.0, They are not working.
Please let us know if we have to make any changes/migration for the same.
Queries & Mutations are working fine.
Thank you!

[StevenACoffman]

My understanding is that newer versions of GraphiQL will have feature parity with GraphQL Playground: https://graphql.org/blog/2020-04-03-web-based-graphql-ides-for-the-win/#the-playground-features-you-love

[StevenACoffman]

@Jonsy13 Can you make an issue describing what has broken for your subscriptions? If you are able to make a minimal open source repository that reproduces your issue, it would greatly facilitate fixing it.

[giautm]

My understanding is that newer versions of GraphiQL will have feature parity with GraphQL Playground: https://graphql.org/blog/2020-04-03-web-based-graphql-ides-for-the-win/#the-playground-features-you-love

But GraphiQL still has not released any 2.x version (even beta/alpha release), we should revert this and wait until GraphiQL is better?

[StevenACoffman]

I'm not opposed to that, but can you enumerate the tracking issues so we would know when "enough" GraphQL playground features have landed into GraphiQL? I see a smattering here https://github.com/orgs/graphql/projects/1/views/1

[ippsav]

It doesn t even support Dark mode.

[frederikhors]

People, please stop complaining.

We are not talking about something fundamental. Open playground executable if you are really interested or use Insomnia or Postman.

Luckily we have people dedicated to this project, just thank these people!

I would completely remove the playground if it were up to me. We do not need it in here.