Implement skeleton loading component for Task area

[seanmiller26]

Package

lib-classifier

Is your feature request related to a problem? Please describe.

FEM pages should display a skeleton loading element for the Task area. This will boost overall aesthetics between classifications while other elements are loading, which may cause unintended quick flashes of content. This change can be in tandem with displaying the default loading element within the subject area. Open to other options as well.

Describe the solution you'd like

Grommet component found here

Mock-up here

Optionally we could go for a full page of skeleton components.