Get the DescriptorScriptPubKeyMans (with private keys) that have the same scriptPubKeys as this LegacyDataSPKM. Does not modify this LegacyDataSPKM.
Declared in <wallet/scriptpubkeyman.h>
std::optional<MigrationData>
MigrateToDescriptor();
The migration data, or nullopt if migration is not possible.