What problem does your feature solve?

From time to time I want to get OperationsMeta<> or LedgerEntryChanges<> out of the TransactionResultMeta. All versions of meta have the operations meta, and getting it out is inconvenient.

What would you like to see?

A .operations() method and a .changes() method on TransactionResultMeta that returns a ref to the internal OperationsMeta<> of each version. For the changes it would be a flat_map'd iterator.