Add performance tests for the app

[ray-millward-tessella]

Description:
It is very easy to write slow code normally when writing a React with Redux app (usually caused by re-rendering components unnecessarily). There are various tools and redux-middleware that can detect this and help to remove them. This is even more true when dealing with micro-frontends as this has the added problem of loading a lot more packages/files (and therefore more requests to the server).

We should write some rudimentary performance tests to track loading time, cpu usage and memory usage over time. These results can then be tracked over time to see if there is a spike from contributing frontends.

Acceptance criteria:

• Performance tests can be run against the app
• Loading time, CPU and memory can be recorded for the app
• The wiki has a page about how to set up and run the performance tests
• The wiki page about performance should record the results of performance tests at various points of the project.