**Revolutionizing Message Tracking: New Metric Unveiled for Success in Mergers!**

**Groundbreaking update allows precise monitoring of successfully merged messages, streamlining performance analysis in the Hubble app.**

Commit Details:

feat: add a new metric for tracking count of successfully merged messages (#2290) ## Why is this change needed? We're currently using hubble.hub.merge_message.count for the message count metric and it looks skewed because some hubs have more messages submitted as bundles than others and each bundle only count as a single message rather than as the number of individual messages inside them. Create a new metric to track successfully merged messages (we already have a metric for errors). ## Merge Checklist _Choose all relevant options below by adding an `x` now or at any time before submitting for review_ - [x] PR title adheres to the [conventional commits](https://www.conventionalcommits.org/en/v1.0.0/) standard - [ ] PR has a [changeset](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#35-adding-changesets) - [x] PR has been tagged with a change label(s) (i.e. documentation, feature, bugfix, or chore) - [ ] PR includes [documentation](https://github.com/farcasterxyz/hub-monorepo/blob/main/CONTRIBUTING.md#32-writing-docs) if necessary. <!-- start pr-codex --> --- ## PR-Codex overview The focus of this PR is to increment a statsd metric when a message submission is successful in the `Hub` class of the Hubble app. ### Detailed summary - Increment statsd metric on successful message submission in `submit_message` method. - Added statsd metric incrementation in the `mergeResult` match block. > ✨ Ask PR-Codex anything about this PR by commenting with `/codex {your question}` <!-- end pr-codex -->