Use "names" for sampled items

As a comment raised on EP1415, if we support sampling on faceZones and patches we have a naming discrepancy between sampling and surfaceFieldValue.

In surfaceFieldValue we select the type (patch/zone/surface etc) and use "names" to specify the selection. For sampledPatch, we specify the type (Eg, type patch), but there we use "patches" to specify the selection instead of "names". If we add faceZones into the mix, we then have "zones" as well.

@Prashant figured that going with "patches" and "zones" might be better. I'm not so sure at the moment. Currently tending towards "names" for both with a silent compatibility handling of "patches".