fix(vsmgr): use bufio.Reader to avoid bufio.Scanner: token too long

[dtynn]

关联的Issues (Related Issues)

fix #230

改动 (Proposed Changes)

使用 bufio.Reader + ReadBytes 实现 类似 Scanner.Scan 的结果，同时避免出现 bufio.Scanner: token too long 这样的问题

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:

• 具有清晰明确的 commit message / All commits have a clear commit message.
• 包含必要的测试用例 / This PR has tests for new functionality or change in behaviour
• 包含必要的指南或文档 / If new user-facing features are introduced, clear usage guidelines and / or documentation updates should be included
• 通过必要的检查项 / All checks are green

[diwufeiwen]

LGTM