## Objective
- Give all the intuitive groups of gizmos their own file
- don't be a breaking change
- don't change Gizmos interface
- eventually do arcs too
- future types of gizmos should be in their own files
- see also https://github.com/bevyengine/bevy/issues/9400
## Solution
- Moved `gizmos.circle`, `gizmos.2d_circle`, and assorted helpers into
`circles.rs`
- Can also do arcs in this MR if y'all want; just figured I should do
one thing at a time.
## Changelog
- Changed
- `gizmos::CircleBuilder` moved to `gizmos::circles::Circle2dBuilder`
- `gizmos::Circle2dBuilder` moved to `gizmos::circles::Circle2dBuilder`
## Migration Guide
- change `gizmos::CircleBuilder` to `gizmos::circles::Circle2dBuilder`
- change `gizmos::Circle2dBuilder` to `gizmos::circles::Circle2dBuilder`
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Co-authored-by: François <mockersf@gmail.com>