GraphQL master FF for review (#18445)

* Initial work on a graphql API

* Added receipts, and more transaction fields.

* Finish receipts, add logs

* Add transactionCount to block

* Add types  and .

* Update Block type to be compatible with ethql

* Rename nonce to transactionCount in Account, to be compatible with ethql

* Update transaction, receipt and log to match ethql

* Add  query operator, for a range of blocks

* Added ommerCount to Block

* Add transactionAt and ommerAt to Block

* Added sendRawTransaction mutation

* Add Call and EstimateGas to graphQL API

* Refactored to use hexutil.Bytes instead of HexBytes

* Replace BigNum with hexutil.Big

* Refactor call and estimateGas to use ethapi struct type

* Replace ethgraphql.Address with common.Address

* Replace ethgraphql.Hash with common.Hash

* Converted most quantities to Long instead of Int

* Add support for logs

* Fix bug in runFilter

* Restructured Transaction to work primarily with headers, so uncle data is reported properly

* Add gasPrice API

* Add protocolVersion API

* Add syncing API

* Moved schema into its own source file

* Move some single use args types into anonymous structs

* Add doc-comments

* Fixed backend fetching to use context

* Added (very) basic tests

* Add documentation to the graphql schema

* Fix reversion for formatting of big numbers

* Correct spelling error

* s/BigInt/Long/

* Update common/types.go

* Fixes in response to review

* Fix lint error

* Updated calls on private functions

* Fix typo in graphql.go

* Rollback ethapi breaking changes for graphql support
Co-Authored-By: Arachnid <arachnid@notdot.net>

vendor/github.com/graph-gophers/graphql-go/README.md

@@ -0,0 +1,100 @@
+# graphql-go [![Sourcegraph](https://sourcegraph.com/github.com/graph-gophers/graphql-go/-/badge.svg)](https://sourcegraph.com/github.com/graph-gophers/graphql-go?badge) [![Build Status](https://semaphoreci.com/api/v1/graph-gophers/graphql-go/branches/master/badge.svg)](https://semaphoreci.com/graph-gophers/graphql-go) [![GoDoc](https://godoc.org/github.com/graph-gophers/graphql-go?status.svg)](https://godoc.org/github.com/graph-gophers/graphql-go)
+
+<p align="center"><img src="docs/img/logo.png" width="300"></p>
+
+The goal of this project is to provide full support of the [GraphQL draft specification](https://facebook.github.io/graphql/draft) with a set of idiomatic, easy to use Go packages.
+
+While still under heavy development (`internal` APIs are almost certainly subject to change), this library is
+safe for production use.
+
+## Features
+
+- minimal API
+- support for `context.Context`
+- support for the `OpenTracing` standard
+- schema type-checking against resolvers
+- resolvers are matched to the schema based on method sets (can resolve a GraphQL schema with a Go interface or Go struct).
+- handles panics in resolvers
+- parallel execution of resolvers
+
+## Roadmap
+
+We're trying out the GitHub Project feature to manage `graphql-go`'s [development roadmap](https://github.com/graph-gophers/graphql-go/projects/1).
+Feedback is welcome and appreciated.
+
+## (Some) Documentation
+
+### Basic Sample
+
+```go
+package main
+
+import (
+        "log"
+        "net/http"
+
+        graphql "github.com/graph-gophers/graphql-go"
+        "github.com/graph-gophers/graphql-go/relay"
+)
+
+type query struct{}
+
+func (_ *query) Hello() string { return "Hello, world!" }
+
+func main() {
+        s := `
+                schema {
+                        query: Query
+                }
+                type Query {
+                        hello: String!
+                }
+        `
+        schema := graphql.MustParseSchema(s, &query{})
+        http.Handle("/query", &relay.Handler{Schema: schema})
+        log.Fatal(http.ListenAndServe(":8080", nil))
+}
+```
+
+To test:
+```sh
+$ curl -XPOST -d '{"query": "{ hello }"}' localhost:8080/query
+```
+
+### Resolvers
+
+A resolver must have one method for each field of the GraphQL type it resolves. The method name has to be [exported](https://golang.org/ref/spec#Exported_identifiers) and match the field's name in a non-case-sensitive way.
+
+The method has up to two arguments:
+
+- Optional `context.Context` argument.
+- Mandatory `*struct { ... }` argument if the corresponding GraphQL field has arguments. The names of the struct fields have to be [exported](https://golang.org/ref/spec#Exported_identifiers) and have to match the names of the GraphQL arguments in a non-case-sensitive way.
+
+The method has up to two results:
+
+- The GraphQL field's value as determined by the resolver.
+- Optional `error` result.
+
+Example for a simple resolver method:
+
+```go
+func (r *helloWorldResolver) Hello() string {
+	return "Hello world!"
+}
+```
+
+The following signature is also allowed:
+
+```go
+func (r *helloWorldResolver) Hello(ctx context.Context) (string, error) {
+	return "Hello world!", nil
+}
+```
+
+### Community Examples
+
+[tonyghita/graphql-go-example](https://github.com/tonyghita/graphql-go-example) - A more "productionized" version of the Star Wars API example given in this repository.
+
+[deltaskelta/graphql-go-pets-example](https://github.com/deltaskelta/graphql-go-pets-example) - graphql-go resolving against a sqlite database
+
+[OscarYuen/go-graphql-starter](https://github.com/OscarYuen/go-graphql-starter) - a starter application integrated with dataloader, psql and basic authentication