Cleanup stats pkg globals

[maryamtahhan]

• Extract the functions to identify node information from the stats package and into a new node package + wrap it in a simple interface that can be used wherever needed.

• Clean up globals in pkg/collector/stats

[github-actions]

🤖 SeineSailor

Here is a concise summary of the pull request changes:

Summary: The pull request refactors the stats package, extracting node-related functions into a new node package, introducing a MetricSets data structure, and simplifying interfaces for better modularity and reusability.

Key Modifications:

1. Node globals cleanup: Removed global variables, introducing a more structured approach with the MetricSets data structure.
2. Node package creation: Extracted functions related to node information from the stats package into a new node package, wrapped in a simple interface.
3. Simplified interfaces: Refactored functions like NewNodeInfo(), Name(), CPUArchitecture(), MetadataFeatureNames(), and MetadataFeatureValues() for easier reuse.

Impact on Codebase:

• Improved modularity and reusability of code
• Simplified interfaces for better maintainability
• Reduced global variables, making the code more structured and easier to understand

Observations/Suggestions:

• The changes seem to be well-structured and follow a clear refactoring strategy.
• It would be beneficial to include additional tests to ensure the new node package and MetricSets data structure are functioning as expected.
• Consider adding documentation or comments to explain the reasoning behind the changes and the benefits of the new node package and MetricSets data structure.