Add "align view to axes" shortcuts

[alice-i-cecile]

What problem does this solve or what need does it fill?

Snapping to various orthographic views is an important part of an 3D modelling workflow.

Bevy does not have built-in support for this.

What solution would you like?

We should borrow both the terminology and the shortcuts directly from Blender. Aligning with existing tools is important for muscle memory.

This should be done by creating a SnapToViewPlugin inside of bevy_camera_controller.

This plugin should be added, with text demonstrating the controls, to the free_camera_controller example.

The plugin should also be added to the scene_viewer example, but the explanatory text should be shorter or absent.

What alternative(s) have you considered?

We should also add a little viewport gizmo (see attached), but that should be done in another PR.

Users who prefer a mouse-driven approach can click on the viewport gizmo to align views.

Additional context

Complements #23435.