`getProcessList`: incorrect handling of multibyte character encoding

[psnet]

Bug is in method getProcessList which returns array of objects with key commandLine which is not correctly handled for multibyte encoding:

• https://github.com/microsoft/vscode-windows-process-tree/blob/main/src/process_worker.cc#L42-L43
• https://github.com/microsoft/vscode-windows-process-tree/blob/main/src/process_commandline.cc#L52-L55
• https://github.com/microsoft/vscode-windows-process-tree/blob/main/src/process.h#L24

so in key commandLine instead of multibyte characters are � symbols.

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This affects vs code process explorer, see issue in vs code microsoft/vscode#219183

[psnet]

@rzhao271 @Tyriar please read