Implement full support for survey filters

[richardolsson]

Only very simple UI has been implemented for the survey-based query filters. For example, there is no way of changing the operator on SurveyOptionFilter, or selecting multiple options. In SurveyResponseFilter, a single question can't be selected (only entire surveys).

[richardolsson]

From the query DSL documentation:

Survey responses (survey_response)

The survey response selection includes people based on a free text search of responses to survey questions.

{
    "type": "survey_response",
    "config": {
        "operator": "in",
        "survey": 2,
        "value": "foobar"
    }
}

The operators are (all operators are case insensitive):

• eq requires that the response is exactly value.
• noteq requires that the response is not exactly value.
• in yields true for responses that contain value.
• notin yields false for responses that contain value.

When survey is specified, all responses in that survey will be searched. Replace the survey attribute with the question attribute, the value of which is the ID of the question, to limit the matching to a single question.