[FDConfig] support set dy-C8 from args

[rsmallblue]

Motivation

Modifications

Usage or Command

python -m fastdeploy.entrypoints.openai.api_server \
       --tensor-parallel-size 1 \
       --host 0.0.0.0 \
       --port $PORT \
       --engine-worker-queue-port 4678 \
       --metrics-port 4877 \
       --max-model-len 131072 \
       --max-num-seqs 12 \
       --no-enable-prefix-caching \
       --gpu-memory-utilization 0.9 \
       --model "$MODEL_PATH" \
       --num-gpu-blocks-override 2048 \
       --quantization '{"dense_quant_type":"block_wise_fp8", "moe_quant_type":"block_wise_fp8", "quantization":"mix_quant", "kv_cache_quant_type":"block_wise_fp8"}' \
       --max-num-batched-tokens 2048 \
       --graph-optimization-config '{"use_cudagraph":true, "use_unique_memory_pool":true, "cudagraph_capture_sizes":[1,2,3,4,5,6,7,8,9,10,11,12]}'

Accuracy Tests

Checklist

• Add at least a tag in the PR title.
  • Tag list: [[FDConfig],[APIServer],[Engine], [Scheduler], [PD Disaggregation], [Executor], [Graph Optimization], [Speculative Decoding], [RL], [Models], [Quantization], [Loader], [OP], [KVCache], [DataProcessor], [BugFix], [Docs], [CI], [Optimization], [Feature], [Benchmark], [Others], [XPU], [HPU], [GCU], [DCU], [Iluvatar], [Metax]]
  • You can add new tags based on the PR content, but the semantics must be clear.
• Format your code, run pre-commit before commit.
• Add unit tests. Please write the reason in this PR if no unit tests.
• Provide accuracy results.
• If the current PR is submitting to the release branch, make sure the PR has been submitted to the develop branch, then cherry-pick it to the release branch with the [Cherry-Pick] PR tag.

[paddle-bot]

Thanks for your contribution!

[carryyu]

LGTM