Clean the code: CommandOutputReceiver

[hydraxman]

Why it's using GBK as encoding? And the IO handling needs improvement.

And there are dup code in:

• SmartTestLog
• XCTestCommandReceiver

[hydraxman]

@zhou9584 please refer to this fix and pick it to the main branch, thanks: https://github.com/microsoft/HydraLab/commit/9d369ae50ab971a8807fb188ed325d59c783f346, https://github.com/microsoft/HydraLab/commit/3d85bc4e52e9edd2aaf13995640ef56a7ccdd8ab

You may create a PR for each above commit.

Some guidelines on picking a commit, you may do it leveraging the desktop app or git command.

• https://docs.github.com/en/desktop/contributing-and-collaborating-using-github-desktop/managing-commits/cherry-picking-a-commit-in-github-desktop
• https://stackoverflow.com/questions/9339429/what-does-cherry-picking-a-commit-with-git-mean