add support for delivery_rules.RewriteResponse objects

[tamsky]

Currently, when running incap site list_incaprule <site_id>,
rules with the following action types are completely missing from all output.

• "action": "RULE_ACTION_RESPONSE_DELETE_HEADER"
• "action": "RULE_ACTION_RESPONSE_REWRITE_HEADER"

and possibly others?

Values are from APIv1 output /api/prov/v1/sites/incapRules/list, as well as listed here:

• https://docs.imperva.com/bundle/cloud-application-security/page/api/sites-api.htm#possible_action_parameter_values_for_delivery_rules:

[joeymoore]

Please look at the dev branch, I have add a ton to this and not merged yet.