Item collecting... mostly

Changelog:

1. The item is added to Bomberman’s inventory on pick up
2. Item effect applies (Remote trigger enable, as a first one)
3. Background music changes after item is picked up
4. Sound effect is played on item collect
5. Player is granted 1000 score on item collect
6. Score is now shown in the UI
7. Refactoring of events binding by using ScriptableObjects for game events
8. Viewport is now more correct: 256x240 instead of 320x240