[CI/UT] Add test for chunk prefill and prefix cache on v1/AscendScheduler (#1505)

### What this PR does / why we need it?
Add test for chunked prefill and prefix cache on v1/AscendScheduler

Covered scenarios:
- `Qwen/Qwen3-0.6B-Base` and `deepseek-ai/DeepSeek-V2-Lite-Chat` ---
multicard CI time increased by 19 min
- `V1 + default scheduler` vs `V1 + default scheduler + enable prefix
cache`
- `V1 + Ascend scheduler` vs `V1 + Ascend scheduler + enable prefix
cache` vs `V1 + Ascend scheduler + enable prefix cache + enable chunked
prefill`
- `Qwen/Qwen3-0.6B-Base` --- singlecard CI time increased by 8 min
- `V1 + Ascend scheduler` vs `V1 + Ascend scheduler + enable chunked
prefill`

should rebase after #1498 and #1446
### Does this PR introduce _any_ user-facing change?
N/A

### How was this patch tested?
CI passed with new added test.

Signed-off-by: MengqingCao <cmq0113@163.com>

tests/e2e/prompts/example.txt

@@ -0,0 +1,8 @@
+vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs.
+Briefly describe the major milestones in the development of artificial intelligence from 1950 to 2020.
+Compare and contrast artificial intelligence with human intelligence in terms of processing information.
+Describe the basic components of a neural network and how it can be trained.
+Write a short story about a robot that dreams for the first time.
+Analyze the impact of the COVID-19 pandemic on global economic structures and future business models.
+Explain the cultural significance of the Mona Lisa painting, and how its perception might vary in Western versus Eastern societies.
+Translate the following English sentence into Japanese, French, and Swahili: 'The early bird catches the worm.'