fix: Compilation fails if Default*Pairs unimplemented in service

[JinnyYi]

fix #760

[Xuanwo]

Maybe default_storage_pairs and storage_features should be required?

How about always add default_storage_pairs and storage_features for services?

[JinnyYi]

Maybe default_storage_pairs and storage_features should be required?

How about always add default_storage_pairs and storage_features for services?

Does it mean default_storage_pairs should be added in namespace.storage.new for all services? Or should we generate DefaultStoragePairs in pairStorageNew struct no matter there's defalt pair or not?

For storage_features, no additional logic is currently required to handle it.

[Xuanwo]

Does it mean default_storage_pairs should be added in namespace.storage.new for all services?

Yes, I think this way could be better.

[JinnyYi]

Does it mean default_storage_pairs should be added in namespace.storage.new for all services?

Yes, I think this way could be better.

Then maybe we don't need to modify go-storage for default_storage_pairs.

[Xuanwo]

Then maybe we don't need to modify go-storage for default_storage_pairs.

How about adding them by default? And finally, we can remove default_storage_pairs in services.toml as they will be auto-added.