Add introspection query

[helper2424]

Hi, I found a small issue, related to the default behavior of graphql. Here is an explanation of this issue:

Explanation

Let's make a test open extension fill Set endpoint field with correct graphql endpoint and cicck to button. In this case extension will send request like the next:

"params" = { 
"query" => "\n  query IntrospectionQuery {\n    __schema {\n      queryType { name }\n      mutationType { name }\n      types {\n        ...FullType\n      }\n      directives {\n        name\n        description\n        locations\n        args {\n          ...InputValue\n        }\n      }\n    }\n  }\n\n  fragment FullType on __Type {\n    kind\n    name\n    description\n    fields(includeDeprecated: true) {\n      name\n      description\n      args {\n        ...InputValue\n      }\n      type {\n        ...TypeRef\n      }\n      isDeprecated\n      deprecationReason\n    }\n    inputFields {\n      ...InputValue\n    }\n    interfaces {\n      ...TypeRef\n    }\n    enumValues(includeDeprecated: true) {\n      name\n      description\n      isDeprecated\n      deprecationReason\n    }\n    possibleTypes {\n      ...TypeRef\n    }\n  }\n\n  fragment InputValue on __InputValue {\n    name\n    description\n    type { ...TypeRef }\n    defaultValue\n  }\n\n  fragment TypeRef on __Type {\n    kind\n    name\n    ofType {\n      kind\n      name\n      ofType {\n        kind\n        name\n        ofType {\n          kind\n          name\n          ofType {\n            kind\n            name\n            ofType {\n              kind\n              name\n              ofType {\n                kind\n                name\n                ofType {\n                  kind\n                  name\n                }\n              }\n            }\n          }\n        }\n      }\n    }\n  }\n" 
}

We see only one field query. Let's make the next, copy body of this query to graphiql explorer and click Execute Query button (don't forget delete \n symbols). In this case, extension will send the next parameters:

params = {
    "query" => "query IntrospectionQuery {    __schema {      queryType { name }      mutationType { name }      types {        ...FullType      }      directives {        name        description        locations        args {          ...InputValue        }      }    }  }  fragment FullType on __Type {    kind    name    description    fields(includeDeprecated: true) {      name      description      args {        ...InputValue      }      type {        ...TypeRef      }      isDeprecated      deprecationReason    }    inputFields {      ...InputValue    }    interfaces {      ...TypeRef    }    enumValues(includeDeprecated: true) {      name      description      isDeprecated      deprecationReason    }    possibleTypes {      ...TypeRef    }  }  fragment InputValue on __InputValue {    name    description    type { ...TypeRef }    defaultValue  }  fragment TypeRef on __Type {    kind    name    ofType {      kind      name      ofType {        kind        name        ofType {          kind          name          ofType {            kind            name            ofType {              kind              name              ofType {                kind                name                ofType {                  kind                  name                }              }            }          }        }      }    }  }",
    "variables" => nil,
    "operationName" => "IntrospectionQuery",
}

Most important difference between these parameters is operationName parameter. Our backend uses this parameter and other backend's could use too.

To avoid this issue I created this PR.

Also, I don't want to create an additional extension in google store and increase confusing, because I created this PR.

[0xF013]

👍