[FEATURE] Show read_used_buffer_size in DashBoard

[rickyma]

Code of Conduct

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• [X] I have searched in the issues and found no similar issues.

Describe the feature

We only show used_buffer_size in the dashboard for now. We should show read_used_buffer_size too.

Motivation

No response

Describe the solution

No response

Additional context

No response

Are you willing to submit PR?

• [ ] Yes I am willing to submit a PR!

[rickyma]

@yl09099 If you have time. PTAL.