New effects

- Added damage particles to player and enemy
- Updated interval damage sound with new dissolving sounds to player and enemy
- Added new particles effect for swimming
- Added die particles effect for enemies
- Updated die sound with new one to match new die effect
- Added pickup sparkle vfx on food picking up
UI Update

- Added ingame pause
- Added settings dialog with sounds and music volume sliders
- Tweaked main menu layout, changed all buttons except of play
Also I did a minor fix of screen size that should make some ui less buggy, for example healthbar was ugly because of Godot zoom, but I think I fixed it just by changing default screen size
