Only load syntax highlighting css when selected
By default, we currently load all syntax highlighting color css as part of application.css. This means that every page load loads all the syntax highlighting colors, even though only one of those themes are enabled at one time.
We should refactor some of our syntax highlighting code to load the correct syntax highlighting css based on what is selected on the user profile. This should help reduce 5% of our loaded css and help the monitor FE team meet their FY2020 Q1 OKR.
cc @tristan.read @adrielsantiago @jivanvl @psimyn