Changes to Estimate a transaction's gas cost.

the calls/items request property type changed from no type to object

added the new optional request property calls/items/contractId

added the new optional request property calls/items/data

added the new optional request property calls/items/dataSuffix

added the new optional request property calls/items/functionArgs

added the new optional request property calls/items/functionName

added the new optional request property calls/items/to

added the new optional request property calls/items/value

added the new required request property accountId

removed the request property account

removed the request property feeSponsorship

added the new optional request property feeSponsorshipId

endpoint added