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/CombatEntry.cpp

@@ -6,8 +6,8 @@
 
 CombatEntry::CombatEntry(DamageSource *source, int time, float health, float damage, CombatTracker::eLOCATION location, float fallDistance)
 {
-	this->source = NULL;
-	if(source != NULL)
+	this->source = nullptr;
+	if(source != nullptr)
 	{
 		// 4J: this might actually be a derived damage source so use copy func
 		this->source = source->copy();
@@ -61,7 +61,7 @@ CombatTracker::eLOCATION CombatEntry::getLocation()
 
 wstring CombatEntry::getAttackerName()
 {
-	return getSource()->getEntity() == NULL ? L"" : getSource()->getEntity()->getNetworkName();
+	return getSource()->getEntity() == nullptr ? L"" : getSource()->getEntity()->getNetworkName();
 }
 
 float CombatEntry::getFallDistance()