logchar is defined as char in Windows environments

Though char is not UTF-8 in Windows environments, LOG4CXX_CHAR:STRING=utf-8 is set and logchar is defined as char, when building with vcpkg.
In Japanese Windows environments, char is Shift_JIS.
Despite claiming UTF-8, log messages are output as-is without any conversion, so Japanese messages are correctly logged in Shift_JIS,
but Unicode-specific characters cannot be logged.

We think LOG4CXX_CHAR:STRING should be set wchar_t and logchar should be defined as wchar_t in Windows environments.

version: 1.4.0
vcpkg tag: 2025.04.09

No source file, test, or entry point is named. Start by tracing the Windows/vcpkg configuration for LOG4CXX_CHAR and the logchar definition, using version 1.4.0 and vcpkg tag 2025.04.09 as context. Done means Windows logging supports Unicode-specific characters without breaking existing Japanese output.

Written by the indexing model from the issue text.