Re: PgAdmin-System_stats extension Patch

Please find the review comments as below:

User Interface:

- The Thread count graph missing the details of handle count and thread count plotting (lines), I can only see the legends.

- The graph details (below the graphs) are not aligned properly.

- The Disk graph is showing nothing apart from the empty grid, and the grid lines are getting out of boundary.  

- If the extension is not available or the user does not have the permission, then the user should get the proper message, currently lots of errors are getting displayed.

Code review:

- system_stat/__init__.py file is not getting used anywhere and the same code has been copied into Dashboard/__init__.py file.

- As per my previous comments, all the generic functions should be in one place. We can not copy one function as it is and paste it into another file and use it.

Ex: Graphs_system_stats.jsx and Graphs.jsx both files contain almost the same functions.

- Does Dashboard_system_stats.css be used anywhere?

- The documentation (rst file) is missing.

- please run 'yarn run pep8' and fix the issues.

Thanks,

Khushboo