chore(gas_price_service): define migration logic for metadata from v0 to v1

[rymnc]

Now that we have concrete types and are integrating v1 of the gas-price-algorithm into gas-price-service, we need to handle upgrades from v0 to v1 which implies overwriting some metadata to the latest version (v1) and having sensible defaults for the da costs.

We should discuss how to do it in this issue

Definition of Done

• TBD: depending on discussions

[rymnc]

cc: @MitchTurner