one home for the reflection in the tests

[FreeAndNil]

One ReflectionExtensions in the test assembly replaces 27 hand written lookups over 13 files.
Test only, no production change, no changelog entry.

// before
=> (string)typeof(LocalSyslogAppender)
  .GetMethod("EscapePercent", BindingFlags.Static | BindingFlags.NonPublic)!
  .Invoke(null, [message])!;

// after
=> typeof(LocalSyslogAppender).Invoke<string>(nameof(EscapePercent), [message]);

A renamed member now fails with its own name instead of a NullReferenceException.