Tech Selection Picker

[QuintillusCFC]

When the user finishes a tech, they are able to choose it from a drop-down list in a popup.

This includes the appropriate advisor portrait and a functional dropdown complete with a pedia icon (see #389 ).

It does not include the "Let me see the big picture option". That can be visible but will not bring up the tech tree.

Once the user selects a tech, it should be the new one they are researcihing.