Parse workspace member manifests

[abhinavgautam01]

Closes #40.

Summary

Updates dependency detection to parse workspace member manifests in addition to root-level manifests.

This now expands and parses:

• Cargo workspace members from root Cargo.toml [workspace].members
• Go workspace members from go.work use entries
• npm/Yarn workspace package manifests from package.json workspaces
• pnpm workspace package manifests from pnpm-workspace.yaml packages

This allows dependency-only tool definitions, such as reqwest, Resty and axios, to be detected when they are declared inside workspace member manifests.

Tests

Adds regression coverage for:

• Cargo workspace member dependencies
• Go workspace member dependencies
• package.json workspace member dependencies
• pnpm workspace member dependencies

Validation

go test ./...