Checkpoints components

This is the collection of checkpoints components within the ui-react module. There are 4 checkpoints components in total.

`BackwardCheckpointsView`

The BackwardCheckpointsView component renders a list of previous checkpoints that the underlying Store can go back to.

The CheckpointView component simply renders the label of a checkpoint.

The CurrentCheckpointView component renders the current checkpoint that the underlying Store is currently on.

The ForwardCheckpointsView component renders a list of future checkpoints that the underlying Store can go forwards to.