Create Invoke-vmscript-PA

Written for PowerActions to use Invoke-VMScript. Invoke commands in the guest OS through PowerActions. Script prompts for guest OS credentials, then prompts for the command to execute. Output is returned in the console window. The script then prompts you to execute another command. Each time you run a command is a new session to the VM. If you want to chain commands together it must be done in a single scriptblock as it is in the invoke-vmscript command.