Custom headers in graphiql.js

[lbhsot]

Is your feature request related to a problem? Please describe.
I'm facing a authentication issue when I use GraphQL playground. My server need a custom header to verify if the request is valid but in graphiql.js have no possible to inject custom header.

Describe the solution you'd like
graphiql.html

    window.GRAPHENE_SETTINGS = {
    {% if subscription_path %}
      subscriptionPath: "{{subscription_path}}",
    {% endif %}
      graphiqlHeaderEditorEnabled: {{ graphiql_header_editor_enabled|yesno:"true,false" }},
      graphiqlShouldPersistHeaders: {{ graphiql_should_persist_headers|yesno:"true,false" }},
      graphiqlInputValueDeprecation: {{ graphiql_input_value_deprecation|yesno:"true,false" }},
    {% if graphiql_headers %}
      graphiqlHeaders: {{ graphiql_headers }}
    {% endif %}
    };

graphiql.js

var headers = {};
  var cookies = ("; " + document.cookie).split("; csrftoken=");
  if (cookies.length == 2) {
    csrftoken = cookies.pop().split(";").shift();
  } else {
    csrftoken = document.querySelector("[name=csrfmiddlewaretoken]").value;
  }
  if (csrftoken) {
    headers['X-CSRFToken'] = csrftoken
  }
  if (GRAPHENE_SETTINGS.graphiqlHeaders) {
    var customHeaders = GRAPHENE_SETTINGS.graphiqlHeaders.split(";");
    for (const header of customHeaders) {
      const [key, value] = header.split(":")
      if (key && value) {
        headers[key] = value
      }
    }
  }

graphene_django/views.py

self.render_graphiql(
  request,
  graphiql_headers=self.custom_headers
  ...
)

Usage

GraphQLView.as_view(..., custom_headers="header_key_1:header_value_1;header_key_2:header_value_2")

Describe alternatives you've considered
No alternatives

Additional context
N/A