feat: add maximum state delta to subnet resource limits in registry

[mraszyk]

This PR adds the maximum state delta to subnet resource limits in the registry's subnet record.

The motivation for this change is to enable tuning the maximum main memory (RAM) usage in addition to the maximum disk usage (covered by the existing field maximum_state_size).

[github-actions]

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Done

[alin-at-dfinity]

Protobuf changes LGTM.

[schneiderstefan]

Title and description are now outdated. Otherwise LGTM