Extend CT0002 to detect enum cast expressions with numeric literals

[Copilot]

The CT0002 enum assignment analyzer previously only flagged direct literal assignments to enum properties but missed cast expressions with numeric literals. This enhancement extends the analyzer to also detect problematic patterns like:

// Previously flagged ✅
statuscode = 3;

// Now also flagged ✅
statuscode = (demo_Entity_statuscode)3;

// Still allowed ✅
statuscode = demo_Entity_statuscode.ValidStatus;
statuscode = (demo_Entity_statuscode)variable;

Changes Made

Enhanced Detection Logic: Modified both AnalyzeEnumAssignment and AnalyzeEnumAssignmentForProperty methods to detect:

• Direct numeric literal assignments (existing behavior)
• Cast expressions where the operand is a numeric literal (new behavior)

Comprehensive Test Coverage: Added new test cases covering:

• Basic cast expressions (EnumPropertyAssignedCastShouldTrigger)
• Dataverse naming patterns (EnumCastWithDataverseNamingPatternShouldTrigger)
• Property initializers with casts (PropertyInitializerWithCastShouldTrigger)
• Member access with casts (MemberAccessEnumAssignedCastShouldTrigger)
• Variable-based casts that should remain allowed (EnumCastFromVariableShouldNotTrigger)

The analyzer now properly encourages developers to use proper enum values instead of casting numeric literals, improving code maintainability and reducing magic numbers in Dataverse-related code.

Fixes #11.

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