Merge pull request #1852 from ProjectMirador/1833-load-window-work

__tests__/integration/mirador/plugins.test.js

__tests__/src/actions/workspace.test.js

__tests__/src/components/App.test.js

__tests__/src/components/WorkspaceAdd.test.js

__tests__/src/components/WorkspaceAddButton.test.js

__tests__/src/reducers/workspace.test.js

src/components/App.js

src/components/ManifestForm.js

src/components/WorkspaceAdd.js

src/components/WorkspaceAddButton.js

src/containers/App.js

src/containers/WorkspaceAdd.js

src/containers/WorkspaceAddButton.js

src/state/actions/action-types.js

src/state/actions/workspace.js

src/state/reducers/workspace.js

src/styles/index.scss