[Feat] Unquantized Linear to nz and control all nz-cast (#3356)

### What this PR does / why we need it?
Currently, when executing to the Linear layer of models in vLLM-Ascend,
the weights format is ND in unquantized case and skipped ascend case.
This PR supplements the execution logic for Linear layer. We use a new
global variable: VLLM_ASCEND_ENABLE_NZ. When VLLM_ASCEND_ENABLE_NZ=1 and
CANN version is 8.3, the weights of the Linear layer will be converted
to FRACTAL_NZ, in both unquantized case and skipped ascend case. We also
use VLLM_ASCEND_ENABLE_NZ to control the existing NZ conversion, such as
w8a8-quantized case.

### Does this PR introduce _any_ user-facing change?
Add a new global variable VLLM_ASCEND_ENABLE_NZ. If you want to use NZ
format, you should set VLLM_ASCEND_ENABLE_NZ=1.

### How was this patch tested?

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

Signed-off-by: anon189Ty <Stari_Falcon@outlook.com>

vllm_ascend/quantization/quant_config.py

@@ -24,8 +24,7 @@ from vllm.distributed import get_tensor_model_parallel_rank
 from vllm.model_executor.layers.fused_moe import (FusedMoE, FusedMoEMethodBase,
                                                   FusedMoeWeightScaleSupported)
 from vllm.model_executor.layers.linear import (LinearBase, LinearMethodBase,
-                                               RowParallelLinear,
-                                               UnquantizedLinearMethod)
+                                               RowParallelLinear)
 from vllm.model_executor.layers.quantization import \
     register_quantization_config
 from vllm.model_executor.layers.quantization.base_config import (
@@ -39,6 +38,7 @@ from vllm.model_executor.utils import set_weight_attrs
 from vllm_ascend.distributed.parallel_state import (get_mlp_tp_group,
                                                     get_otp_group)
 from vllm_ascend.ops.common_fused_moe import AscendUnquantizedFusedMoEMethod
+from vllm_ascend.ops.linear import AscendUnquantizedLinearMethod
 from vllm_ascend.utils import (ASCEND_QUANTIZATION_METHOD, mlp_tp_enable,
                                oproj_tp_enable)
 
@@ -101,7 +101,7 @@ class AscendQuantConfig(QuantizationConfig):
         if isinstance(layer, LinearBase):
             if self.is_layer_skipped_ascend(prefix,
                                             self.packed_modules_mapping):
-                return UnquantizedLinearMethod()
+                return AscendUnquantizedLinearMethod()
             return AscendLinearMethod(self, prefix,
                                       self.packed_modules_mapping)
         elif isinstance(layer, Attention) and \