Gizmo 3d grids (#12430)

# Objective

- Adds 3d grids, suggestion of #9400

## Solution

- Added 3d grids (grids spanning all three dimensions, not flat grids)
to bevy_gizmos

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## Changelog

- `gizmos.grid(...)` and `gizmos.grid_2d(...)` now return a
`GridBuilder2d`.
- Added `gizmos.grid_3d(...)` which returns a `GridBuilder3d`.
- The difference between them is basically only that `GridBuilder3d`
exposes some methods for configuring the z axis while the 2d version
doesn't.
- Allowed for drawing the outer edges along a specific axis by calling
`.outer_edges_x()`, etc. on the builder.

## Additional information
Please note that I have not added the 3d grid to any example as not to
clutter them.
Here is an image of what the 3d grid looks like:
<img width="1440" alt="Screenshot 2024-03-12 at 02 19 55"
src="https://github.com/bevyengine/bevy/assets/62256001/4cd3b7de-cf2c-4f05-8a79-920a4dd804b8">

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Co-authored-by: Alice Cecile <[email protected]>