[Common] tensor format in struct

[Common] tensor format in struct

Move enum flag - tensor_format into tensors-info struct.

To pass flexible tensors to filter sub-plugins, we should indicate tensor format in tensors-info struct, not tensors-config.
Internally tensors-config struct is used for caps negotiation.

TODO: need discussion, should we separate format in each tensor info, so that each mem chunk can express its format. (then, nnstreamer will combine memories: static+flexible in gst-buffer.)

Signed-off-by: Jaeyun <jy1210.jung@samsung.com>