KYLIN-5238 add cleanup unreferenced cube_statistics

[liuzhao-lz]

Proposed changes

在 kylin4 的StorageCleanupJob 中增加对无引用的 cube_stataistics 数据清理，我认为是有意义的：

1. 可以降低无用数据占用的存储空间，同时避免过多无用小文件对nn的压力
2. 默认情况下清理无引用的 cube_stataistics 数据，但可以通过 -cleanupCubeStatistics false 禁用

Branch to commit

• [ ] Branch kylin3 for v2.x to v3.x
• [x] Branch kylin4 for v4.x
• [ ] Branch kylin5 for v5.x

Types of changes

What types of changes does your code introduce to Kylin? Put an x in the boxes that apply

• [ ] Bugfix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)
• [ ] Documentation Update (if none of the other choices apply)

Checklist

Put an x in the boxes that apply. You can also fill these out after creating the PR. If you're unsure about any of them, don't hesitate to ask. We're here to help! This is simply a reminder of what we are going to look for before merging your code.

• [x] I have created an issue on Kylin's jira, and have described the bug/feature there in detail
• [x] Commit messages in my PR start with the related jira ID, like "KYLIN-0000 Make Kylin project open-source"
• [ ] Compiling and unit tests pass locally with my changes
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] I have added necessary documentation (if appropriate)
• [ ] Any dependent changes have been merged

Further comments

If this is a relatively large or complex change, kick off the discussion at [email protected] or [email protected] by explaining why you chose the solution you did and what alternatives you considered, etc...

[hit-lacus]

This patch looks good to me.