[NNCF] Add get_bias_shape_legacy function (openvinotoolkit#3249)

Changes:

Moved and renamed backend-specific class method from common layer
attributes in nncf/common/graph/layer_attributes.py to self-contained
function in nncf/common/graph/utils.py
- layer_attributes.get_bias_shape ->
get_bias_shape_legacy(layer_attributes: WeightedLayerAttributes)

Reason for changes:

(openvinotoolkit#3249) Torch and Tensorflow backend-specific methods need to be removed
from common layer attributes and all related calls need to be replaced
by their corresponding legacy function calls

Author: shumaari

nncf/common/graph/utils.py

@@ -178,3 +178,15 @@ def get_target_dim_for_compression_legacy(
         if layer_attributes.transpose:
             return 1
         return 0
+
+
+def get_bias_shape_legacy(
+    layer_attributes: WeightedLayerAttributes) -> int:
+    """
+    Returns hard-coded bias shape only for Torch and Tensorflow models.
+
+    :param layer_attributes: layer attributes of NNCFNode.
+    :return: bias shape.
+    """
+    if isinstance(layer_attributes, LinearLayerAttributes):
+        return layer_attributes.out_features if layer_attributes.with_bias is True else 0