Include observability backend plugin in this repository

[joshuali925]

Is your feature request related to a problem? Please describe.
currently this repo only includes the frontend code, but it needs backend to work

Describe the solution you'd like
refactor project structure to a sub directory, and add backend code

Describe alternatives you've considered
A clear and concise description of any alternative solutions or features you've considered.

Additional context
Add any other context or screenshots about the feature request here.