CCIP - make required config types public and update legacy snapshot function args

[ogtownsend]

• A few of the config poller related structs were private when they were defined in cl-ccip. However, since they now live in cl-common and we need to access them in cl-ccip and other repos, they need to be public.
• Updates GetAllConfigLegacySnapshot(...) function args since it needs to have knowledge of which chain is the dest chain when constructing the batch read query

[winder]

Isn't destChainSelector implicit? Thats the only chain the accessor is able to read from.

[ogtownsend]

@winder it's for this check: https://github.com/smartcontractkit/chainlink-ccip/blob/main/pkg/reader/ccip.go#L1224

the accessor needs to know which configs it should fetch (unless want to remove that check and attempt to fetch them all)

[ogtownsend]

I guess we could just check if destChain is contained within sourceChainSelectors, but that might not be exhaustive if sourceChainSelectors only has a subset of chains

[winder]

Is that check staying outside of the accessor? Maybe we need a way for the accessor user to get the associated selector.

[ogtownsend]

No, that check would be within the accessor since that function is very specific to the chain reader, here is a WIP: https://github.com/smartcontractkit/chainlink-ccip/compare/cal-implement-GetAllConfigLegacySnapshot?expand=1