feat: export validator rewards (fees)

[fmorency]

This pull request introduces several changes, including dependency updates, code refactoring for improved error handling, and the addition of a new FeesCollector feature. Below is a summary of the most important changes grouped by theme.

Dependency Updates:

• Added cosmossdk.io/math v1.5.3 to the go.mod file.
• Removed unused dependencies github.com/davecgh/go-spew and github.com/pmezard/go-difflib from the go.mod file. [1] [2]

Code Refactoring:

• Refactored error handling in constructors like NewDenomInfoCollector, NewExcludedSupplyCollector, and NewTokenCountCollector to use a more concise else if pattern for checking client.Conn. [1] [2] [3]
• Updated the Collect method in ExcludedSupplyCollector to use the gRPC client's context (c.grpcClient.Ctx) for better context propagation.

New Feature:

• Introduced a new FeesCollector in pkg/collectors/autodetect/manifestd/fees.go to monitor transaction fees locked in validators. This includes:
  • Initialization with error handling for gRPC client validation.
  • Methods for describing and collecting Prometheus metrics.
  • Support for querying validator rewards via gRPC and aggregating results.

[Copilot]

Pull Request Overview

This PR refactors collector constructors for clearer error handling, updates dependencies, and adds a new FeesCollector to expose validator fee metrics via Prometheus.

• Consolidate client nil/connection checks in existing collectors with else if patterns
• Update gRPC context usage in ExcludedSupplyCollector for consistent propagation
• Introduce FeesCollector feature with metric descriptions, concurrent gRPC queries, and Prometheus reporting

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
pkg/collectors/autodetect/manifestd/token_count.go	Refactored constructor error checks into if … else if block
pkg/collectors/autodetect/manifestd/excluded_supply.go	Switched from context.Background() to c.grpcClient.Ctx
pkg/collectors/autodetect/manifestd/denom_info.go	Refactored constructor error checks into if … else if block
pkg/collectors/autodetect/manifestd/fees.go	New FeesCollector with Prometheus metrics and concurrent gRPC
go.mod	Added cosmossdk.io/math and removed unused dependencies

Comments suppressed due to low confidence (1)

pkg/collectors/autodetect/manifestd/fees.go:1

• The new FeesCollector adds significant logic and error paths but lacks accompanying unit or integration tests. Please add tests covering successful fee aggregation and each error scenario.

//go:build manifest_node_exporter

[jgryffindor]

Tested ACK, looks good! This is out on a canary in testnet.