Refactor Builder pattern examples to ensure compatibility with earlie…

[omarbitar97]

…r C# versions (C# 4.0) by replacing modern C# syntax (e.g., interpolated strings and expression-bodied members) with older syntax. Corrected potential access issues and improved code consistency for clearer understanding.

Refactored the Builder pattern example code for compatibility with older C# versions (C# 4.0), addressing issues such as the use of interpolated strings and expression-bodied members. Corrected access issues and ensured that methods and properties were properly implemented to avoid compilation errors. Updated the vehicle and robot-building examples to ensure they are clear, functional, and compliant with older syntax rules.