Add NSIS plugin support and extraction functionality

- Implemented plugin API in `pluginapi.cpp` and `pluginapi.h` for NSIS integration.
- Added resource files `resource.h` and `resource.rc` for versioning and resource management.
- Created `ExtractCallbackConsole` class to handle extraction progress and user input.
- Developed main extraction logic in `Main.cpp` and `MainAr.cpp` for handling archives.
- Introduced user input utilities in `UserInputUtils2.cpp` and `UserInputUtils2.h` for password handling and user prompts.
- Added break signal handling in `NSISBreak.cpp` and `NSISBreak.h` for graceful interruption of extraction processes.
- Included standard header `StdAfx.h` for precompiled headers and common includes.

build.cmd

@@ -0,0 +1,7 @@
+@echo off
+:: Generic wrapper for build_plugin.py
+:: Usage: build.cmd [--7zip-version 19.00|25.01|26.00|zstd] [--toolset 2022|2026|auto] [...]
+::   Default: --7zip-version 26.00 --toolset auto
+setlocal
+python "%~dp0build_plugin.py" %*
+exit /b %errorlevel%