Cleanup CPU plugin
Cleanup CPU plugin

Summary:
Addressing code review feedback from previous 3 diffs.

* Don't return draft when using immer
* Move functions out of component to module level
* Make executeShell async and simplify callsites
* Add onStopMonitor to cleanup function
* Add uniform spacing by adding Layout.Container around titles
* Disable searchbar on both tables
* Use Toolbar

Reviewed By: mweststrate

Differential Revision: D28091565

fbshipit-source-id: 533d2491e6f48a9eaaa64b1a6cf76eea2e7189a5

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