Windows support

[retrixe]

• Launch wrapper that unloads writer.exe, WebView2Loader.dll and webview.dll to %LOCALAPPDATA%\writer then launches them.
• Support for device discovery.
• Replace dd with writing to the disk directly on Windows.
• Unmount all partitions before writing and check if disk is exclusively locked.
• Support privilege elevation for dd replacement.
• Better device discovery with partition names like E:
• E2E test Windows reliably before releasing binaries.