Feat/tanlang/add api to manager p2p net in meassager

[LinZexiao]

关联的Issues (Related Issues)

involve #5129

改动 (Proposed Changes)

• move genesis sub module from /fixtures/networks to pkg/genesis
• add api to manager p2p net in masssager

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 #5185 (a42a202) into master (15088ed) will increase coverage by 0%.
The diff coverage is 23%.

@@          Coverage Diff           @@
##           master   #5185   +/-   ##
======================================
  Coverage      24%     25%           
======================================
  Files         592     592           
  Lines       65338   65383   +45     
======================================
+ Hits        16306   16386   +80     
+ Misses      46889   46852   -37     
- Partials     2143    2145    +2