Free camera helper UI

[Zemanzo]

Description The free camera has quite some features, but how to use it is not well explained to the user.

Minimum Acceptance Criteria

• [ ] When the free camera is active for the first time, show a graphic that explains how to control the camera. (Click & hold; WASD + QE)
• [ ] Once they have successfully moved the camera, remove the graphic.
• [ ] Display speed changes on screen

Is blocked by the following issues #31 Probably best if #81 is also done before this one