feat: add GET /v1/targeted-messaging/:outreachId/chains/:chainId/safes/:safeAddress

[iamacook]

Partially resolves #2323

Summary

Targeted messaging currently targets Safes and signers (that have yet submitted responses).

This adds a new (GET /v1/targeted-messaging/:outreachId/chains/:chainId/safes/:safeAddress) route, returning a response should a safeAddress be targeted by a given outreachId.

type Response = {
  outreachId: number;
  address: `0x${string}`;
}

Changes

• Add GET /v1/targeted-messaging/:outreachId/chains/:chainId/safes/:safeAddress route
• Add new route-level TargetedSafe entity
• Add appropriate test coverage

[PooyaRaki]

Question: How do we make sure that the safe address does not appear in a campaign?

[PooyaRaki]

Looks good to me. I only have a question but that's not a blocker so I'll approve it.

[iamacook]

How do we make sure that the safe address does not appear in a campaign?

As per agreement, this will be used in conjunction with the existing feature flags of the Config Service (client-side). We intend to iterate on targeted features.