♻️ Use .sh extension on shell compatible terminals on Windows

[teikitel]

On Windows with Git Bash, when hitting CTRL+C when running for example a java CLI from command launcher, the terminal crashes because the underlying execution is actually passed down a .bat script execution.

In Git Bash, we actually don't need to use the .bat version. The .sh version will even be more efficient.

To detect that we're in Git Bash, we use the environment variable MSYSTEM.

Here we also rename occurrences of "os" used as OS name "osName" to avoid confusions with the "os" library.

Change-Id: I5bed4dc2282533d75bceccba67ad05b9c1094f0d

[bhou]

I don't have a windows environment at hand, I am wondering the situation in WSL environment, what will be the osName, and should we handle it here as well? But that could be another PR.

[ndrufin-crto]

I don't have a windows environment at hand, I am wondering the situation in WSL environment, what will be the osName, and should we handle it here as well? But that could be another PR.

In WSL the OS name is Unix based like Ubuntu.

[teikitel]

In fact I test on Windows and it's not enough.

As the command launcher is a native process, the underlying subcommand is forked as native process.

• Launching a command with no extension will cause Windows process to try and find a .bat or .exe associated file
• Launching a bash script with .sh extension will fail because .sh is not a valid executable extension

I'll push another approach to handle signals from command-launcher and allow for a more graceful shutdown.