Add support for Client Credentials flow

[dancrumb]

Is your feature request related to a problem? Please describe.

I'd like to be able to authenticate via client credentials in the Altair client

Describe the solution you'd like

Really, I'm looking for an update to the OAuth 2.0 Grant type options to include Client Credentials.

It would take the Client ID, Client Secret and Token URLs, with optional (or required, if you prefer) Scope.

Describe alternatives you've considered

There's no other alternative, beyond me sending my own request via cURL and then using the Bearer token Auth option

Additional context

No. I'm happy to add further context, if needed, but I think this one is probably fairly self explantory.

[imolorhe]

@dancrumb this should be available in v8.0.1. Although this is available now, I wanted to talk about the alternatives. Altair comes with the pre-request feature that allows you execute some logic and update the environment before actually running your GraphQL request. This was the option that was used before we added the authentication options, and is still a valid option to go with if a specific authentication method is not yet supported.