XDRill: Operation level functions

[chowbao]

The Operation level functions is similar to the ledger_operation.go example code from the design doc

• Create new struct for the Operation level functions

  type Operation struct {
    OperationIndex  int32
    Operation       xdr.Operation
  }
  

  • May need to add

    Transaction     LedgerTransaction
    LedgerCloseMeta xdr.LedgerCloseMeta
  

• Create function to GetOperations() from transactions
• Define functions needed for
  • history_operations transforms
  • history_assets transforms
  • history_trades transforms

[chowbao]

Blocked by #5595