Replace request With Native HTTP Stream Download in Fetch Providers

[yashkohli88]

Overview

This PR removes the deprecated request package and replaces its usage for downloading packages across all supported ecosystems with a new getStream function.
It also updates dependencies and modernizes related testing and fetch logic.

Key Changes

• New getStream function in lib/fetch.js exported to provide streaming downloads using axios.
• Replaced all usage of request in package fetchers across:
  • Conda
  • Debian
  • Go
  • Maven
  • NPM
  • Composer
  • PyPI
  • RubyGems
• Removed the deprecated request dependency from package.json.
• Updated axios to version 1.11.0.
• Updated tests and mocks to match new streaming approach, including proxyquire stubs.
• Addressed formatting issues and cleaned up code.

Motivation

• The request package is deprecated and no longer maintained.
• Modern HTTP libraries like axios offer better security, support, and community engagement.
• Uniform download logic across all ecosystem fetchers simplifies maintenance and enables enhancements.

Testing

• Updated and added unit tests for getStream and affected providers.
• Tests cover both direct URL and options object, as well as default headers and error handling.
• Updated all test and mock code to use Promise-based streaming stubs for fetchers.

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Closes: #573