[metrics] Add serveral observability metrics (#3868)

* Add several observability metrics

* [wenxin-tools-584] 【可观测性】支持查看本节点的并发数、剩余block_size、排队请求数等信息

* adjust some metrics and md files

* trigger ci

* adjust ci file

* trigger ci

* trigger ci

---------

Co-authored-by: K11OntheBoat <your_email@example.com>
Co-authored-by: Jiang-Jia-Jun <163579578+Jiang-Jia-Jun@users.noreply.github.com>

fastdeploy/output/token_processor.py

@@ -282,6 +282,7 @@ class TokenProcessor:
         main_process_metrics.batch_size.set(
             self.resource_manager.max_num_seqs - self.resource_manager.available_batch()
         )
+        main_process_metrics.available_batch_size.set(self.resource_manager.available_batch())
 
         if task_id in self.tokens_counter:
             del self.tokens_counter[task_id]