Setup storage_version for bridging pallets

[bkontur]

Closes: paritytech/parity-bridges-common#2947

[ggwpez]

I dont see how this is needed. cc @liamaharon

If there is an issue with pallets that do not have storage versions, then we should fix that and not work around it by setting versions. Not having a version for a pallet should be perfectly fine.

[bkchr]

Yes, this should not be needed.

[liamaharon]

Not needed, storage version is zero if omitted.

That said, there's no harm in specifying it explicitly if people want to establish that pattern in their pallets.

[bkontur]

I dont see how this is needed. cc @liamaharon

If there is an issue with pallets that do not have storage versions, then we should fix that and not work around it by setting versions. Not having a version for a pallet should be perfectly fine.

No, no, there is no problem :)

My intentions with this PR are just to prepare the bridging pallets for future migrations, which will be introduced with BridgesV2. Additionally, we have other issues that will require migrations. I just thought it would be a good idea to add #[pallet::storage_version] and prepare pallets for migrations.

But let's not complicate, we will add this when needed.