[BCF-3381] - Add LatestHead to ChainService

[ilija42]

core ref: be3ae431096e0d240e282b4c3233a2d3bb5d832e
starknet ref: 1accbe13d8372cef26c7d252e3e06a182d74ee64
solana ref: 052a8297ee098a740e037ac737f7158025644b32

• core PR
• cosmos PR
• solana PR
• starknet PR
• chainlink-ccip

[jmank88]

Are unix timestamps with second precision be sufficiently general? Or do we need more precision? (I suppose we could just add a field later for nanos or something 🤔)

[ilija42]

We can add more precision if needed later, not sure if all chains even give more precision?

[jmank88]

Alternatively, we could use the official protobuf timestamp, which is (seconds int64, nanos int32): https://pkg.go.dev/google.golang.org/protobuf/types/known/timestamppb#Timestamp

[ilija42]

I always find Unix the most universal, what advantage do you see in using protobuf seconds?

[jmank88]

I always find Unix the most universal, what advantage do you see in using protobuf seconds?

If we expect use add nanos later, then it could be cleaner to use this built-in type instead, which comes with helper methods.