chore: add provider type to all providers metrics

🧿 Current issues / What's wrong ?

Some provider metrics are not labeled by type (json/image).

💊 Fixes / Solution

Add the type label to remaining providers metrics without it

🚧 Changes

Add type label to all remaining providers metrics without it
Migrate the providersInstrumentation middleware declaration inside metrics.ts. Inside of using of declaring the middleware usage next to each router, we move it inside the metrics.ts file, and use a kind of hook system to attach it to the correct route. This will reduce the metrics code footprint, instrumentation code should the most unobtrusive possible.

🛠️ Tests

Upload some JSON and image (via postman or other way)
Visit http://localhost:3000/metrics
The providers_return_count metric should have a new type label value, with value either image of json

Codecov Report

Patch coverage has no change and project coverage change: -0.53% :warning:

Comparison is base (6e0e0b1) 27.25% compared to head (20afeea) 26.73%.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #169 +/- ## ========================================== - Coverage 27.25% 26.73% -0.53% ========================================== Files 14 14 Lines 565 576 +11 Branches 30 30 ========================================== Hits 154 154 - Misses 403 414 +11 Partials 8 8 ``` | [Files Changed](https://app.codecov.io/gh/snapshot-labs/pineapple/pull/169?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=snapshot-labs) | Coverage Δ | | |---|---|---| | [src/metrics.ts](https://app.codecov.io/gh/snapshot-labs/pineapple/pull/169?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=snapshot-labs#diff-c3JjL21ldHJpY3MudHM=) | `0.00% <0.00%> (ø)` | | | [src/providers/index.ts](https://app.codecov.io/gh/snapshot-labs/pineapple/pull/169?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=snapshot-labs#diff-c3JjL3Byb3ZpZGVycy9pbmRleC50cw==) | `0.00% <0.00%> (ø)` | | | [src/rpc.ts](https://app.codecov.io/gh/snapshot-labs/pineapple/pull/169?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=snapshot-labs#diff-c3JjL3JwYy50cw==) | `0.00% <0.00%> (ø)` | | | [src/upload.ts](https://app.codecov.io/gh/snapshot-labs/pineapple/pull/169?src=pr&el=tree&utm_medium=referral&utm_source=github&utm_content=comment&utm_campaign=pr+comments&utm_term=snapshot-labs#diff-c3JjL3VwbG9hZC50cw==) | `0.00% <0.00%> (ø)` | |

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snapshot-labs / pineapple