Load blocks and objects behind player when in third-persion front-view

[lhofhansl]

2nd attempt. This time send a bit to the server if the client is in 3rd person front mode. That setting is not stored in the player database.

An alternative would be to actually send the client's camera orientation to the server. That way in the future we can allow for alternate camera angles - although for that we have the camera API PR.

Also fixes: #12770

To do

This PR is Ready for Review.

How to test

Load any world. Go to 3rd person front view. Observer that blocks and objects behind the player are loaded.

[lhofhansl]

What do we think here in general? For complete correctness we should not only pass the player location and orientation but also the camera position and orientation so that the server can retrieve the correct blocks from the viewpoint of the camera. This is more of a quick fix for the most immediate problem.

[Desour]

What do we think here in general? For complete correctness we should not only pass the player location and orientation but also the camera position and orientation so that the server can retrieve the correct blocks from the viewpoint of the camera. This is more of a quick fix for the most immediate problem.

The server would also have to check if the camera pos is valid (i.e. reachable with the current set eye offset).

I feel like this quick fix is sufficient for now.

[Desour]

LGTM.