Broken camera placement for observers

[elexis]

TLDR: For alpha 23, we must add code to center the camera location in observermode.

When playing games, opening skirmish/scenario maps in atlas or generating random maps in atlas, the camera focuses on an entity of the player.

If the map doesn't come with any player entities (about impossible and if possible, likely wants to use a cinematic path), or more likely:

if the game is started in observer/replaymode, then the random map determines the initial camera location

r20370 removed some code that pretends to center the camera.

But the impression that ParseCamera in MapReader.cpp is unusably broken is very strong.

So it seems there is no use case to save a camera position in any of the map types.

So the code could be removed instead of fixed. The camera location could then be comptued in the same place for both players and observers.

The Player component also has camera positioning code which appears unused.