Improve message inspection

[thorin-schiffer]

Currently the project listing

And inspection

look quite basic and don't represent the conversation flow. The messages will be organized corresponding to their threads structure and also link to the thread's Gmail page.

The inspect page would show the previous conversation history, showing the folding grade, subjects and timestamps. The messages would look similar to the timeline from #27 or #28 and also may include the project events this message is related to.