Fix parallax on the islands sky background

[Booplicate]

Problem:

Incorrect parallax effect on the background
Fixes #10452

Fix:

1. added extra info in debug mode, now shows how much the sprite can move
2. reduced zoom on the background to reduce its parallax

Testing:

1. run the game, open the islands
2. enable debug mode (v), verify the background has smaller offsets than the islands
3. move around, zoom in/out, click on stuff, verify nothing broke

[Booplicate]

@ThePotatoGuy, @Legendkiller21 if you guys are up to review smol stuff for next update, check this