feat: Add SPDD and DRDD modules with optional historical storage

[whankinsiv]

This PR:

• Adds the spdd_state module to optionally store stake pool delegation distributions by epoch.
• Moves the /spdd REST endpoint from accounts_state to spdd_state.
• Updates caryatid_module_rest_server to v0.14.0 across applicable modules.
• Enhances the /spdd endpoint to accept an optional epoch query parameter (Ex: /spdd?epoch=209).

In this implementation, the /spdd endpoint is always registered, while state creation and population are determined by the store-spdd config flag in omnibus.toml. When store-spdd is set to false, the handler receives a None state and returns a 503 error: "SPDD storage is disabled by configuration."

[whankinsiv]

I've also included the drdd_state implementation in this PR, as it aligns closely with the logic in spdd_state. The /drdd endpoint now supports an optional epoch query parameter, enabling retrieval of historical DRep delegation distributions.

[alexwoods]

Looks good, probably only the incorrect label in the info_span of drdd_state really needs addressing.

[alexwoods]

Looks good, but check the comment on OrdMap

[alexwoods]

This looks very similar to what's going on in drdd, just a slightly different contains check. For handling rollback state we currently have StateHistory in the common lib that works if your top level per-block state is a an imbl container. It might be nice to add a helper function alongside it for things like this where you have a new state to compare differences with the current one, to apply to an imbl::OrdMap clone of the current state. I can't help but feel that StateHistory might be extendable to work for epochs and retain all snapshots too.

[whankinsiv]

I'll expand StateHistory to handle epoch-based states and add a helper function to compare differences between imbl:OrdMaps when inserting.

[sandtreader]

@whankinsiv There are unresolved conflicts now which I can't directly fix - I suspect this has to do with 'cargo fmt' changes in AccountsState. I hope once we have 'cargo fmt' on CI this kind of thing will stop!