Modernize project: migrate to .NET 10, CPM, and WCOM templates

[devlead]

• Update target framework from .NET 9.0 to .NET 10.0
• Migrate to Central Package Management (CPM)
  • Add Directory.Packages.props for centralized package version management
  • Remove package versions from .csproj files
  • Add nuget.config with package source mapping
• Update Azure Pipelines to use WCOM templates
  • Replace manual build steps with dotnetweb/stages.yml template
  • Configure container build for Azure Functions
  • Switch to WCOM pool and common-build-variables
• Update README prerequisites and configuration
  • Update .NET SDK requirement to 10.0
  • Update tool versions (VS 2022 17.10+, VS Code 1.90+)
  • Change config separator from ':' to '__' for cross-platform compatibility
  • Add Docker .env file example
• Add .editorconfig with comprehensive C# coding standards
• Add Constants.cs for centralized queue name constant
• Refactor code formatting and style
  • Apply expression-bodied members where appropriate
  • Fix spacing and formatting inconsistencies
  • Update queue references to use Constants class
• Update solution file format (.sln to .slnx)
• Remove Microsoft.SourceLink.GitHub package reference