Add capability to do cone search for closest galaxy in search box

[albireox]

Is your feature request related to a problem? Please describe. It would be useful to be able to introduce some coordinates in the search box in marvin-web and get the closest galaxy without, say, 1 arcmin.

Describe the solution you'd like Have the search box detect when the input are coordinates and use the marvin query machinery to retrieve the closest galaxy. If there is a match, redirect to the Galaxy Page for that galaxy.

[havok2063]

I'll add that this is technically doable currently by inputting e.g. radial(232.5447,48.69,1.0) in the search box. We can either document this better or modify the query page to add more helper functions/buttons.

[albireox]

I think that while doable in the query page this is a common enough feature that we may want to implement it in the normal search box (the mangaid/plateifu one). Without really knowing what I'm saying it doesn't look difficult to implement and it would be a pretty useful feature.