refactor: Use package local metrics

[SuperQ]

Part 2 (#1578)

Improve performance of metrics by moving them to the package that needs them. This reduces the overhead to a simple atomic increment for basic counters like cache hits/misses. This also uses promauto to avoid the second step of having to register metrics.

[codecov[bot]]

Codecov Report

Attention: Patch coverage is 81.81818% with 2 lines in your changes missing coverage. Please review.

Project coverage is 93.85%. Comparing base (fe84ab8) to head (823c916). Report is 147 commits behind head on main.

Files with missing lines	Patch %	Lines
lists/list_cache.go	77.77%	2 Missing :warning:

Additional details and impacted files

```diff @@ Coverage Diff @@ ## main #1605 +/- ## ========================================== - Coverage 93.88% 93.85% -0.04% ========================================== Files 78 80 +2 Lines 6361 6574 +213 ========================================== + Hits 5972 6170 +198 - Misses 300 320 +20 + Partials 89 84 -5 ```

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[SuperQ]

I'm working on an improvement to the tests using the client_golang testutil.

[github-actions[bot]]

This PR is stale because it has been open 45 days with no activity. Remove stale label or comment or this will be closed in 10 days.

[SuperQ]

Not really stale, but I haven't had a chance to work on the coverage change.

[SuperQ]

@0xERR0R, how do you feel about the coverage change here?

[0xERR0R]

@0xERR0R, how do you feel about the coverage change here?

It is always nice to cover more code, but it is not an ultimate goal to have 100% coverage :)