Refactor batch API, improve errors for LambdaView

• TezosToolkit.batch has been deprecated in favour of a batch() method on the contract and wallet API. See preliminary docs here: https://github.com/ecadlabs/taquito/pull/648/files and many examples of usage in our integration tests.
• LamdbaView returns a useful error message when a signer is not configured in Taquito
• More intergration-tests to cover the Wallet API
• Many small fixes to the Taquito documentation

This release is published to npmjs under the next tag.

You can install it with the command npm i @taquito/[email protected]

Or the handy ncu command to update all your Taquito dependancies using this command:

ncu -u --target newest --filter '/^@taquito.*$/'