[RFC]: support sequence parallelism by pass

Motivation.

Flash Comm V1 (FC1) is a feature that is similiar to sequence parallelism. FC1 is implemented by custom op in vllm-ascend. However, it is not supported for VL models. When extending FC1 to VL models, we meet 2 problems: 1: The VL model lacks an embedding-layer reduce-scatter operation, resulting in redundant all-gather during the first step.

2: In Qwen3-VL, deepstack_input_embeds is added after computation at each layer, but the shape does not match. We must add chunk before layernorm.

Proposed Change.

Implement sequence parallelism by pass:

• Support VL Dense model https://github.com/vllm-project/vllm-ascend/pull/5632
• Suport INT8 dynamic quant
• Support VL MoE models https://github.com/vllm-project/vllm-ascend/pull/7044
• Support LLM dense and MoE models
• Matmul reducescatter pass and allgather matmul pass
• Support model runner v2
• compitable with FC2 and FC3
• Make FC1 only applicable in eager mode

Feedback Period.

No response

CC List.

@wxsIcey @ApsarasX

Any Other Things.

No response