GPU Python: Implement gpu.texture.from_image

It can be useful to replace `image.bindcode` and `image.gl_load`.

Used for example in https://docs.blender.org/api/current/gpu.html#d-image

Reviewed By: brecht

Differential Revision: https://developer.blender.org/D10458

source/blender/python/gpu/gpu_py_api.c

@@ -73,6 +73,9 @@ PyObject *BPyInit_gpu(void)
   PyModule_AddObject(mod, "state", (submodule = bpygpu_state_init()));
   PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
 
+  PyModule_AddObject(mod, "texture", (submodule = bpygpu_texture_init()));
+  PyDict_SetItem(sys_modules, PyModule_GetNameObject(submodule), submodule);
+
   return mod;
 }