TimeControl is initialized too late

[JonasGilg]

Describe the Bug

I wanted to set the initial observer position to the ISS, but this uncovered a bug. When the observer is moved to the starting position the simulation time is still at 2000-01-01 00:00:00.000.

Steps to reproduce the behavior:

1. Load a spice kernel with a satellite (that doesn't exist in 2000)
2. Set the start position to the satellites center and the frame to J2000 in the config
3. Launch CosmoScout VR
4. An error is thrown in the console: [W] cs-scene .......... CelestialObserver::moveTo failed: Insufficient ephemeris data has been loaded to compute the state of 0 (SOLAR SYSTEM BARYCENTER) relative to -125544 (ISS) at the ephemeris epoch 2000 JAN 01 12:00:00.000.

Expected Behavior

The simulation time should be set before the observer is moved.