Fix lightprobe creation from python data API

### Description of the problem

Until now, it is only possible to correctly add a lightprobe in python via an operator:
`bpy.ops.object.lightprobe_add()`

### Description of the proposed solution

The idea of this patch is to fix the lack of consistency lightprobe creation without operator.
It allow creation of different lightprobe type directly via `bpy.data.lightprobes.new(name, type)` (such as for curves).

In order to make it possible I had to:
1. Add a function `BKE_lightprobe_configure` in charge of lightprobe settings configuration (avoid code redundancy)
2. Allow an object to take lightprobe datablock as data during is initialization.

### A short example of this patch usage

```
lp = bpy.data.lightprobes.new('some_name','PLANAR')

bpy.data.objects.new('toto', lp)

```

Reviewed By: fclem

Differential Revision: https://developer.blender.org/D6396

1 files changed, 24 insertions, 0 deletions

diff --git a/source/blender/blenkernel/intern/lightprobe.c b/source/blender/blenkernel/intern/lightprobe.c
index 06f1ee5050b..3a9c1c8ae1d 100644
--- a/source/blender/blenkernel/intern/lightprobe.c
+++ b/source/blender/blenkernel/intern/lightprobe.c
@@ -41,6 +41,30 @@ void BKE_lightprobe_init(LightProbe *probe)
   MEMCPY_STRUCT_AFTER(probe, DNA_struct_default_get(LightProbe), id);
 }
 
+void BKE_lightprobe_configure(LightProbe *probe, const short lightprobe_type)
+{
+  probe->type = lightprobe_type;
+
+  switch (probe->type) {
+    case LIGHTPROBE_TYPE_GRID:
+      probe->distinf = 0.3f;
+      probe->falloff = 1.0f;
+      probe->clipsta = 0.01f;
+      break;
+    case LIGHTPROBE_TYPE_PLANAR:
+      probe->distinf = 0.1f;
+      probe->falloff = 0.5f;
+      probe->clipsta = 0.001f;
+      break;
+    case LIGHTPROBE_TYPE_CUBE:
+      probe->attenuation_type = LIGHTPROBE_SHAPE_ELIPSOID;
+      break;
+    default:
+      BLI_assert(!"LightProbe type not configured.");
+      break;
+  }
+}
+
 void *BKE_lightprobe_add(Main *bmain, const char *name)
 {
   LightProbe *probe;