Add support for System.DateOnly and System.TimeOnly types

[WanjohiSammy]

Related Issues

Fixes #439

Description

This PR adds support for System.DateOnly and System.TimeOnly types in OData Connected Service code generation, replacing the legacy Microsoft.OData.Edm.Date and Microsoft.OData.Edm.TimeOfDay types.

Changes Made

Core Template Changes

• Renamed internal property DateTypeName -> DateOnlyTypeName
• Renamed internal property TimeOfDayTypeName -> TimeOnlyTypeName
• Updated type mapping for EdmPrimitiveTypeKind.Date to generate System.DateOnly
• Updated type mapping for EdmPrimitiveTypeKind.TimeOfDay to generate System.TimeOnly
• Applied changes to both C# and VB.NET templates

Test Infrastructure

• Added .NET Framework 4.7.2 compatibility layer in test helpers
  • Tests target .NET Framework 4.7.2 because Visual Studio extensions don't support .NET 10 yet
  • Added type replacement logic to convert System.DateOnly/TimeOnly back to EDM types during test compilation

Breaking Changes

BREAKING CHANGE: Generated code now uses System.DateOnly and System.TimeOnly instead of Microsoft.OData.Edm.Date and Microsoft.OData.Edm.TimeOfDay.

Impact:

• Projects targeting .NET 6 or later: Will work seamlessly with modern types
• Projects targeting .NET Framework or older .NET versions: Will need to use OData EDM library types or upgrade to .NET 6+

Migration Guide:

• If your project targets .NET 6+, no changes needed - the new types are part of the BCL
• If your project targets .NET Framework or .NET Standard 2.0, you may need to:
  • Continue using the previous version of OData Connected Service, OR
  • Upgrade to .NET 6+ (recommended)

[WanjohiSammy]

Close as duplicate of #442