Make it possible to set extradata in preResponseEvent and pass it on

Problem/Motivation

Right now its hard to set data in the preResponseEvent that you might want to pass on to the postResponseEvent for logging reasons. We need a solution for that.

Useful for request time for instance.

Proposed resolution

• Add a method to the PreGenerateResponseEvent called setState (or come up with a better name) that takes key and a mixed value.
• Add a method to the PreGenerateResponseEvent called getStates that responds with an array of all data set in the setState.
• Add a method to the PreGenerateResponseEvent called getState that takes a key and responds with mixed data set in setState.
• Add a method to the PostGenerateResponseEvent called setState (or come up with a better name) that takes key and a mixed value.
• Add a method to the PostGenerateResponseEvent called getStates that responds with an array of all data set in the setState.
• Add a method to the PostGenerateResponseEvent called getState that takes a key and responds with mixed data set in setState.
• Transfer the data from the PreGenerateResponseEvent getStates to PostGenerateResponseEvent setState so it can be transferred.

Remaining tasks

User interface changes

API changes

Data model changes