feat: refactor market event

[diwufeiwen]

关联的Issues (Related Issues)

ref filecoin-project/venus#5484

改动 (Proposed Changes)

附注 (Additional Info)

自查清单 (Checklist)

在你认为本 PR 满足被审阅的标准之前，需要确保 / Before you mark the PR ready for review, please make sure that:

• 符合Venus项目管理规范中关于PR的相关标准 / The PR follows the PR standards set out in the Venus project management guidelines
• 具有清晰明确的commit message / All commits have a clear commit message.
• 包含相关的的测试用例或者不需要新增测试用例 / This PR has tests for new functionality or change in behaviour or not need to add new tests.
• 包含相关的的指南以及文档或者不需要新增文档 / This PR has updated usage guidelines and documentation or not need
• 通过必要的检查项 / All checks are green

[codecov-commenter]

Codecov Report

Merging #112 (453305b) into master (84fdba8) will increase coverage by 0.11%.
The diff coverage is 96.66%.

📣 This organization is not using Codecov’s GitHub App Integration. We recommend you install it so Codecov can continue to function properly for your repositories. Learn more

Additional details and impacted files

@@            Coverage Diff             @@
##           master     #112      +/-   ##
==========================================
+ Coverage   63.17%   63.29%   +0.11%     
==========================================
  Files          30       30              
  Lines        2197     2204       +7     
==========================================
+ Hits         1388     1395       +7     
  Misses        736      736              
  Partials       73       73              

Flag	Coverage Δ
unittests	63.29% <96.66%> (+0.11%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
api/rpc_impl.go	93.75% <80.00%> (ø)
marketevent/market_client.go	67.59% <100.00%> (ø)
marketevent/market_event.go	90.57% <100.00%> (+0.13%)	⬆️
testhelper/testhelper.go	96.82% <100.00%> (+0.27%)	⬆️

[simlecode]

lgtm