Make expected format for line breaks in host data consistent

[broeder-xceptance]

There are multiple ways to provide host data when starting a new EC2 instance. When multiple IP/URL pairs are provided and separated by \n, the line break will have a different number of escaping slashes in the end, depending on which command was used to start the instance (e.g. \n for one command and \\n for another command). This can lead to invalid host data formats.

Example:

• Use interactive mode and provide host data
  • Provided host data:
    • 1.1.1.1 example1.com\n2.2.2.2 example2.com
  • Resulting user data in EC2 console:
    • {"acPassword": "password", "hostData": "1.1.1.1 example1.com\n2.2.2.2 example2.com"}
• Use interactive mode and provide user data
  • Provided user data:
    • {"acPassword": "password", "hostData": "1.1.1.1 example1.com\n2.2.2.2 example2.com"}
  • Resulting user data in EC2 console:
    • {"acPassword": "password", "hostData": "1.1.1.1 example1.com
2.2.2.2 example2.com"}
• Providing host data in non-interactive mode
  • Provided host data parameter:
    • --hostData "1.1.1.1 example1.com\n2.2.2.2 example2.com"
  • Resulting user data in EC2 console:
    • {"acPassword": "password", "hostData": "1.1.1.1 example1.com\\n2.2.2.2 example2.com"}

The behavior should either be more consistent (i.e. entering \n should have the same results for all available commands) or communicated better (i.e. there should be some explanatory text stating what format to use).