[FEAT-UI]: Create Savepoint Canvas Step of Storm Selection

[martyheynbah]

We decided to break out the storm tracks and savepoint selection into 2 steps with the Storm Selection tab. We already have the storm tracks tab, but we need to:

• add a step to the stepper for savepoints
• create the savepoints UI with a canvas and reach - savepoint selector based off figma wireframe

This ticket is just UI, we will have another ticket for functionality (connecting reaches to savepoints)