* all: rename internal 1559 gas fields, add support for graphql

* cmd/evm/testdata, core: use public 1559 gas names on API surfaces

This is the initial implementation of EIP-1559 in packages core/types and core.
Mining, RPC, etc. will be added in subsequent commits.

Co-authored-by: Marius van der Wijden <m.vanderwijden@live.de>
Co-authored-by: lightclient@protonmail.com <lightclient@protonmail.com>
Co-authored-by: Felix Lange <fjl@twurst.com>

This adds support for EIP-2718 typed transactions as well as EIP-2930
access list transactions (tx type 1). These EIPs are scheduled for the
Berlin fork.

There very few changes to existing APIs in core/types, and several new APIs
to deal with access list transactions. In particular, there are two new
constructor functions for transactions: types.NewTx and types.SignNewTx.
Since the canonical encoding of typed transactions is not RLP-compatible,
Transaction now has new methods for encoding and decoding: MarshalBinary
and UnmarshalBinary.

The existing EIP-155 signer does not support the new transaction types.
All code dealing with transaction signatures should be updated to use the
newer EIP-2930 signer. To make this easier for future updates, we have
added new constructor functions for types.Signer: types.LatestSigner and
types.LatestSignerForChainID. 

This change also adds support for the YoloV3 testnet.

Co-authored-by: Martin Holst Swende <martin@swende.se>
Co-authored-by: Felix Lange <fjl@twurst.com>
Co-authored-by: Ryan Schneider <ryanleeschneider@gmail.com>

* Fix typo in interfaces.go

* Update interfaces.go

Fix a spelling mistake in comment

There is no need to depend on the old context package now that the
minimum Go version is 1.7. The move to "context" eliminates our weird
vendoring setup. Some vendored code still uses golang.org/x/net/context
and it is now vendored in the normal way.

This change triggered new vet checks around context.WithTimeout which
didn't fire with golang.org/x/net/context.

This significantly reduces the dependency closure of ethclient, which no
longer depends on core/vm as of this change.

All uses of vm.Logs are replaced by []*types.Log. NewLog is gone too,
the constructor simply returned a literal.

ethclient now returns ethereum.NotFound if the server returns null and
no error while accessing blockchain data.

The light client cannot provide arbitrary transactions. The change to
split transaction access into its own interface emphasizes that
transactions should not be relied on and recommends use of logs.