Add ability to search for workspaces

[andywynkoop]

On the workspace select page, on the right side under 'Choose a different workspace', add a feature to search for a workspace by name and display the top five matching workspaces (if any) or 'No results'
Backend:

• Implement a workspace search api endpoint
• workspaceSearchReducer to store an array of workspaces (id and name)
• searchWorkspaces thunk action creator and receiveSearchWorkspaces
• Add component to workspace select page
• Add relevant info to container