[Performance] Investigate and implement userTiming API metrics to a "problematic page"

[unlikelyzero]

Is your feature request related to a problem? Please describe.
We should understand and implement UX Centric performance measurements for problematic parts of the application. A great first implementation would be the time it takes a plot to render on a Display Layouts

Describe the solution you'd like

• Investigate the userTiming API
• Present to team
• Implement a single timing metric on a problematic page like Display Layouts

Additional context
https://github.com/ux-capture/ux-capture is a wrapper for the existing API

[shefalijoshi]

Please add testing instructions.

[khalidadil]

@unlikelyzero Is this just adding the performance mark to the View Large? What work was done under this issue?

[unlikelyzero]

@shefalijoshi this landed in 2.0.3 and will need to be retested at some point in the future

[unlikelyzero]

Will consider this closed as a part of yesterday's testathon