Update v0.5.2

-4 new mid game enemies were added:

1. The Destroyer MK1, a fast and devastating ship that will use its smart targeting Heavy Autocannon

along with a couple of Autocannons to overwhelm the player with its forward speed.

1. The Y Fighter, the normal enemy variant of the Heavy Y Fighter boss. It uses 4 cannons to poke

at the player from a long distance.

3)The Galliot MK1, a slow turning but heavily armed small-medium ship that boasts 2 Heavy Autocannons

covering both its front and back. Due to its slow turn speed, it will have the player at one of its sides,

where both Heavy Autocannons can fire at them along with a non rotating Cannon which exists at each side.

4)The Interceptor Fighter, with large sideways move speed, it will circle the player, trying to predict

their movement with its Heavy Plasma Cannon, while firing 2 non rotating dual autocannons forward,

as a form of area denial.

-All Weapon material costs were reduced depending on their previous cost. Normal Weapon costs were reduced by (roughly) 500 to 1000, Heavy Weapon costs were reduced by 1500 to 2500, small Anti Missile Weapon costs were reduced by 100 to 150, and Nuclear Missile's cost was reduced from 15000 to 12000, but its explosion damage was reverted back to 15000 from 20000.

-Nukes finally don't have 16x increased invisible blast radius (newly created bug). TLDR, nukes are now safe to use (as long as you stay outside of their blast radius).

-Fixed a bug where all weapon groups would be enabled at the start of a Stage, even if they weren't supposed to.

-minor performance optimizations.