Fix Message initialization to correctly handle thread IDs for both POCO
and non-POCO threads. When Thread::current() returns null (std::thread,
main thread, etc.), use NativeThreadInfo to get the OS thread ID instead
of leaving _tid as zero.

Rename NativeThreadInfo::id() to NativeThreadInfo::osTid() to match the
Thread::currentOsTid() naming convention and clarify that both return
the same kernel-level thread identifier (not the POCO sequential ID).

Additional changes:
- Add comprehensive documentation to NativeThreadInfo explaining its
  purpose and when to use it vs Thread::current()
- Fix LoggerTest warning by removing pessimizing std::move in return
- Update all platform implementations (POSIX, WIN32, WINCE, VxWorks)

This ensures the %I format specifier in PatternFormatter shows:
- POCO thread ID (1, 2, 3...) for Poco::Thread instances
- OS thread ID for non-POCO threads (std::thread, main thread, etc.)

testFormatThreadName was failing in CI because it expected the POCO
thread ID to be 1, but in a full test run, many threads are created
before this test (by ThreadingTestSuite, etc.), resulting in higher IDs.

The test now compares against the actual thread's ID (thr.id()) instead
of a hard-coded value, making it robust regardless of test order.

… functions selection #3333

- Thread_WIN32: Use MultiByteToWideChar with CP_UTF8 in setCurrentNameImpl
  instead of byte-by-byte iterator copy. The old conversion was incorrect
  for non-ASCII characters (e.g., Japanese thread names).

- LoggerTest: Add bounds check (parts.size() >= 5) before accessing vector
  elements to prevent undefined behavior if log message format is unexpected.

Thread_WIN32.cpp:
- Use dynamic loading for SetThreadDescription/GetThreadDescription
  via GetProcAddress for compatibility with pre-Windows 10 1607
- setCurrentNameImpl tries modern API first, falls back to legacy
  exception method (0x406D1388) for older Windows/debuggers
- Remove redundant processthreadsapi.h and stringapiset.h includes
  (already included via windows.h)

LoggerTest.cpp:
- Simplify loop condition (remove redundant npos check)
- Fix code style (braces on new lines)