[Feature] support aclgraph for model runner v2 (#7110)

### What this PR does / why we need it?
This PR aims to support aclgraph for model runner v2, please see RFC
#5208. The PR contains these modifications:
- adapt to newest commit of vllm main branch.
- supply a unified interface of extra forward context for both model
runner v1 and model runner v2.
- implement graph mode for main model. 

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?

- vLLM version: v0.16.0
- vLLM main:
4034c3d32e

---------

Signed-off-by: Ronald1995 <ronaldautomobile@163.com>

vllm_ascend/ops/fused_moe/moe_comm_method.py

@@ -19,11 +19,10 @@ from abc import ABC, abstractmethod
 from dataclasses import dataclass
 
 import torch
-from vllm.forward_context import get_forward_context
 from vllm.model_executor.layers.fused_moe import FusedMoEConfig
 
 import vllm_ascend.envs as envs_ascend
-from vllm_ascend.ascend_forward_context import MoECommType
+from vllm_ascend.ascend_forward_context import _EXTRA_CTX, MoECommType
 from vllm_ascend.ops.fused_moe.moe_mlp import unified_apply_mlp
 from vllm_ascend.ops.fused_moe.prepare_finalize import (
     PrepareAndFinalize,
@@ -135,7 +134,7 @@ class MoECommMethod(ABC):
         # Check constraints
         assert hidden_states.dtype in [torch.float32, torch.float16, torch.bfloat16, torch.int8]
 
-        moe_comm_method = get_forward_context().moe_comm_method
+        moe_comm_method = _EXTRA_CTX.moe_comm_method
         assert moe_comm_method is not None, "Missing communication context"
 
         before_dispatch_evt = torch.npu.current_stream().record_event()