Annotations Spike: Explore default dragging behavior

### Background
When dragging on a giraffe graph, the default behavior is to zoom in on the section dragged. This interaction will probably not work when annotating a graph. Explore different ways of handling this.

### Ideas
- Have the drag handler be a function passed in. Have ui implement the default handler and pass that in unless it's in annotation mode

Start by examining the giraffe graph's current drag-to-zoom behavior and how annotation mode is represented in the repository. Compare the proposed injectable drag handler with other interaction patterns, and define a chosen behavior and validation approach before implementation.

Written by the indexing model from the issue text.