Implement GetBlockAtHeight for Archive Node invoker

[koko1123]

Problem

Some flow batch scanner scripts fail on the Archive node because thefvm instance in the the invoker module of the archive node does not implement methods like GetBlockAtHeight and GetAccount

Solution

Implement these methods and bugfix the errors caused by a GetAccount calls in the fvm

Testing

The flow-batch-scanner example scripts should produce the same output as Execution nodes