Update the ingest/change Change struct to always pass LCM if available

[chowbao]

The ingest/change Change struct has a field for Ledger *xdr.LedgerCloseMeta found here

It is not always populated depending on the Change.Reason (because LCM can be populated inside the change.Transaction). I believe it is more beneficial to always populate Change.Ledger no matter the change reason as it will always be able to be associated with a LedgerCloseMeta.

Supplementally we should evaluate whether or not it makes sense to always propagate OperationIndex and Transaction as well if they exist. This will depend on if they are only available for their correlated Change.Reason or if their current scope is not all inclusive of valid OperationIndex/Transaction data

Edit: OperationIndex and Transaction are always populated when relevant as it is already