Optimize the gossip method by modifying peer states

In the VRF-based randomized leader election, the method `request_proposal_to_any` is awkward. If the tendermint module introduce a new peer state "priority", it can request proposals only to the nodes whose priorities are the highest.

从 `request_proposal_to_any` 方法开始，跟踪基于 VRF 的随机化 leader 选举流程，直至 Tendermint 的 peer 状态处理。确定应如何指定新的 `priority` 状态和最高优先级的 proposal 请求，然后记录预期行为以及证明 gossip 仅将目标指向符合条件的高优先级节点所需的测试。

由索引模型根据 Issue 内容生成。