Add flag log icon to non-autoflagged posts

[Andrew5057]

Autoflagged posts like this one currently have a red flag icon next to the post title, which links to the post's flag log. A similar icon for non-autoflagged posts would make the flag log easier to find.

See Makyen's message for one potential implementation of this.

I think any implementation should at least follow these guidelines:

• Autoflagged posts, unflagged posts, and posts that have been manually flagged only should each have their own version of the icon.
• Each icon should have its own hovertext. The current hovertext reads "This post had flags cast on it" - that hovertext should vary between the 3(?) icons to make their meanings clear.
• Accessibility should be a central focus. Designing for color blindness comes to mind - green vs red flags is a poor differentiator, etc.

[tripleee]

The code already has a number of conditions for when to display the flag icon and there is one for "not autoflagged" but it is not exposed by the current logic (hollow instead of filled, so nicely meets the usability concerns). I've looked at it a few weeks back so I'm just collecting my notes here in the hope that I could revisit this at some point. It was slightly too complex to figure out in my head but it should not be hard per se to reorder things so that it is shown when we want it to be.