Add option in .properties file to enable/disable specific test oracles

[AML14]

This will allow us to test an API in different ways. For example, if we enable oracle 2XX/4XX, we are forced to generate valid inputs, and we can only create faulty variants for those parameters which are not strings. However, if we only check 5XX status codes, we can generate any inputs that may break the SUT more easily.

This issue will require updating the RESTAssuredWriter.