[long_seq_Feat] support chunk prefill (#4158)

### What this PR does / why we need it?
1、qwen GQA attention_v1 optim
2、DeepSeek MLA refactor, all gather q -> all gather kv 
3、modelrunner refactor for chunk prefill, we remove some code not use

- vLLM version: v0.11.0
- vLLM main:
2918c1b49c

---------

Signed-off-by: LookAround <lixushi@huawei.com>
Signed-off-by: Delphine-Nic <tanwenqin@huawei.com>
Co-authored-by: Delphine-Nic <tanwenqin@huawei.com>

tests/ut/attention/test_mla_v1.py

@@ -484,9 +484,6 @@ class TestAscendMLAImpl(TestBase):
         chunk_ctx.chunk_seq_lens = [torch.tensor([8])]
         chunk_ctx.chunk_seq_lens_npu = [torch.tensor([8])]
         chunk_ctx.starts = [torch.tensor([0])]
-        chunk_ctx.max_chunk_num = 1
-        chunk_ctx.mask_for_non_zero_chunk = [True]
-        chunk_ctx.local_chunked_kv_lens = [[[[8]]]]
 
         prefill_meta = MagicMock()
         prefill_meta.chunked_context = chunk_ctx