Adding a step tour on a class field doesn't work

Steps to reproduce:

• Create a tour with a step containing a class field
  • e.g.: Code.TestClass_input

Results:

• Tour starts, but that step is skipped, because the CSS selector is not a valid one.

• Adding a "\" to escape the dot "." in the CSS selector breaks the whole tour. It doesn't start anymore:

  SyntaxError: JSON.parse: bad control character in string literal at line 1 column 336 of the JSON data