Modernize project codebase (#906)

* Fixed boats falling and a TP glitch #266

* Replaced every C-style cast with C++ ones

* Replaced every C-style cast with C++ ones

* Fixed boats falling and a TP glitch #266

* Updated NULL to nullptr and fixing some type issues

* Modernized and fixed a few bugs

- Replaced most instances of `NULL` with `nullptr`.
- Replaced most `shared_ptr(new ...)` with `make_shared`.
- Removed the `nullptr` macro as it was interfering with the actual nullptr keyword in some instances.

* Fixing more conflicts

* Replace int loops with size_t and start work on overrides

* Add safety checks and fix a issue with vector going OOR

Minecraft.World/CactusTile.cpp

@@ -11,8 +11,8 @@
 CactusTile::CactusTile(int id) : Tile(id, Material::cactus,isSolidRender())
 {
 	setTicking(true);
-	iconTop = NULL;
-	iconBottom = NULL;
+	iconTop = nullptr;
+	iconBottom = nullptr;
 }
 
 void CactusTile::tick(Level *level, int x, int y, int z, Random *random)