Add missing links to the civilopedia

**Issue by [chaorace](https://github.com/chaorace)**
_Monday Jan 09, 2017 at 08:41 GMT_
_Originally opened as https://github.com/CQUI-Org/cqui/issues/235_

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For example:

* Clicking a unit you don't own in the normal selection mode should open the civilopedia
* ~~Right-clicking a leader portrait from the diplomacy ribbon should open the civilopedia~~ (this now opens the trade screen)
* Right-clicking a tech/civic from the world tracker should open the civilopedia
* Clicking the current production item from the production menu should open the civilopedia
* Right-clicking an improvement build item from the builder unit panel should open the civilopedia
* Clicking icons in your civ's self-info page in the diplomacy view should open their corresponding civilopedia entries

[More info](https://www.reddit.com/r/civ/comments/5mqlkl/long_feedback_on_civ6_from_a_longtime_series_fan/)

Start by locating the Lua UI handlers for unit selection, the world tracker, production menu, builder panel, and diplomacy self-info page. Check how each surface currently opens details, then make the applicable clicks or right-clicks open the corresponding Civilopedia entry. Verify each listed interaction in the game, excluding the diplomacy leader portrait item noted as already changed.

Written by the indexing model from the issue text.