Handle discrepancy of process launching on Windows between different versions of Java

[smashery]

This fixes a test failure when running acceptance tests with Java 8 on Windows.

At some point in the past, it seems that OpenJDK decided to change the behaviour of ProcessBuilder on Windows, to partially-but-not-entirely start doing some argv-like escaping when converting to a Windows command line.

Seems like it's just better for us to avoid letting Java do any smarts, and just create a command line string that is passed straight to the CreateProcess API, which we know has been consistent since the dawn of time.

Verification

On both older (Java 8? 11?) and newer (tested on Java 16):

• In MSF, check out the new_cmd_exec branch
• Build the java solution (run make when in a directory adjacent to MSF)
• Create a java payload (java/meterpreter/reverse_tcp), and run it on Windows
• Catch the shell in MSF - validate that it warns that ext_server_stdapi.jar is being used
• loadpath test/modules/
• use post/test/cmd_exec
• run with the captured session
• Validate that all tests pass