Read from CSV: retarget net10.0, fix the discarded configuration, add the missing data file and real tests

[vladimir-pecanac-main]

Updates the sample behind the "How to Read Data From a CSV File in C#" article.

• Both projects move from net6.0 to net10.0.
• CsvHelper 27.2.1 to 33.1.0, Microsoft.NET.Test.Sdk 16.11.0 to 18.10.0, MSTest 2.2.7 to 4.4.0, coverlet.collector 3.1.0 to 10.0.1.
• ReadPersons() built a CsvConfiguration with HasHeaderRecord = false and then handed the CsvReader a CultureInfo instead, so the configuration was discarded and the first data row was silently consumed as a header. The configuration is now passed to the reader, and the records are materialised with ToList() so the file is actually read.
• filePersons.csv was missing from the repository, so the built console app threw FileNotFoundException before any CsvHelper code ran. It is added and copied to the output folder.
• File-scoped namespaces, and PersonMap moves out of the global namespace into ReadFromCsv.
• The single test asserted only that 3 == 3 and its expected data contradicted its own CSV input. It now asserts field values, with the expected data matching the input and dates parsed with InvariantCulture. New tests cover the headerless read, a quoted comma, comments with and without AllowComments, TextFieldParser against string.Split, and ReadingExceptionOccurred skipping a bad row.

Build and tests: 0 warnings, 0 errors, 7 of 7 passing on .NET 10.0.10 (SDK 10.0.302).