[POC] Enable Ubuntu 24.04 LTS support with GCC 13 compatibility

[Nox-MSFT]

Major Changes:

• Add Ubuntu 24.04 platform support with GCC 13.3.0
• Disable Delivery Optimization (not available on 24.04)
• Add Azure Storage SDK GCC 12+ compatibility patch
• Update documentation for all supported platforms

Build System Changes:

• scripts/install-deps.sh: GCC version detection and conditional patching

  • Skip gcc-8 installation on Ubuntu 24.04+
  • Auto-detect GCC version and apply Azure Storage SDK patch for GCC >= 12
  • Skip DO client installation on Ubuntu 24.04
  • Change workspace directory to .workspace/
  • Fix file ownership issues

• scripts/build.sh: Ubuntu 24.04 detection

  • Auto-detect Ubuntu 24.04 and disable DO build
  • Update workspace path to .workspace/

CMake Changes:

• CMakeLists.txt: Add ADUC_BUILD_WITH_DELIVERY_OPTIMIZATION option
• src/extensions/content_downloaders/CMakeLists.txt: Conditional DO build
• packages/CMakeLists.txt: Platform-specific package dependencies
• cmake/agentRules.cmake: Conditional DO SDK linking

Package Changes:

• packages/debian/postinst: Smart downloader registration
  • Register DO downloader if available, otherwise curl

Patches:

• scripts/patches/azure-storage-sdk-base64-cstdint.patch: New patch
  • Fixes missing includes for GCC 12+
  • Applied to Azure Storage SDK base64.hpp, base64.cpp, uuid.hpp

Documentation:

• README.md: Updated platform support table

  • Added Ubuntu 20.04, Debian 11/12 platforms
  • Added platform-specific notes for DO availability
  • Fixed Quick Start command to include unit tests flag

• docs/agent-reference/how-to-build-agent-code.md: Comprehensive rewrite

  • Expanded platform support table with all distributions
  • Build dependencies table with LKG versions
  • Runtime dependencies section
  • Detailed per-dependency build instructions
  • GCC 12+ patch documentation with automatic detection
  • Platform-specific build notes for each OS version
  • Troubleshooting section

Tested:

• Full build successful on Ubuntu 24.04 with GCC 13.3.0
• All 148 unit tests passed (100%)
• Debian package created: deviceupdate-agent_1.2.0_amd64.deb
• curl content downloader registered as primary downloader