Start the rate fetcher

[mkysel]

This might need a better process lifecycle manager, but this is good enough now.

[graphite-app]

How to use the Graphite Merge Queue

Add either label to this PR to merge it via the merge queue:

• Queue - adds this PR to the back of the merge queue
• Hotfix - for urgent hot fixes, skip the queue and merge this PR next

You must have a Graphite account in order to use the merge queue. Sign up using this link.

An organization admin has enabled the Graphite Merge Queue in this repository.

Please do not merge from GitHub as this will restart CI on PRs being processed by the merge queue.

[macroscopeapp]

Start the rates fetcher in cmd.replication.main.setupFeeCalculator to initialize the rate fetcher as part of starting the rate fetcher

In cmd/replication/main.go, the setupFeeCalculator helper creates a rates fetcher with fees.NewContractRatesFetcher, calls Start() on the returned fetcher, and returns an error if Start() fails before constructing and returning the FeeCalculator. See main.go.

📍Where to Start

Start with setupFeeCalculator in main.go, focusing on the creation of fees.NewContractRatesFetcher and the subsequent Start() invocation and error handling.

---

Macroscope summarized 04a593b.