[Patch] Add highlight consumer/supplier button to fabinfo

[hreintke]

I always have trouble locating suppliers and consumers of a factory
This patch changes the consumer/supplier labels on the Connections tab from fabinfo dialog to buttons.

Click on the buttons highlights the consumer and or supplier factories on the map.

See attached image for example

[prissi]

They are usually too far away for me to see, but why not. Incorporated in r10037

[Yona-TYT]

Hey, it happens to me that when I focus on an object sometimes I don't get it, why not implement this to each focused object if you use the arrow button or the eye in title of the windows? .

[Ranran]

What appearance does this provide when in "hide all buildings" mode?

[Ranran]

What appearance does this provide when in "hide all buildings" mode?

As I feared, this is not working in hide buildings mode. That is, all factories are always highlighted in red, so this feature is meaningless. What do you guys think about this?

What I came up with to deal with this
1) Display a prominent cursor over the head of the factory.
2) Add a border to the factory image. For example, display a 4px wide border in yellow like this.

[prissi]

Just unhide buildings for this works too ... It is just a keypress.

[Leartin]

1) Display a prominent cursor over the head of the factory.

Whether it's something needed for this issue in particular or not, I feel like a "position indication cursor" as an object similar to the floating money messages (spawns at a certain position and stays there for ~ 5 seconds, does not rescale with zoom) would be neat and could be useful in other cases as well. Eg. any go-to button could spawn such a position indicator at the very place you jump to, since it can be a hassle to find if you happen to be zoomed out; scenario-makers could spawn it for clear indication etc.