Scoru,Proto: version storage values

Context

Child of !5465 (merged).

I think it closes #2906 (closed). There a still others values that are not versioned, I introduced the versioned for sc_rollup_*_repr types but not for the values such as string, Raw_level, int32 etc.

Values that are in the storage but are not versioned:

• Sc_rollups.Kind.t: it's already a variant so we can probably easily extend the kinds
• Script_repr.lazy_expr
• Raw_level_repr.t
• Sc_rollup_commitment_repr.Hash.t: I did not version this, I don't think that's necessary
• int32
• Sc_rollup_repr.Staker.t: it's a public key hash..

Manually testing the MR

N/A

Checklist

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