CDClient cleanup and optimization (#1023)

* CDClient cleanup and optimization

- Use static function to get table name
- Remove unused GetName function
- Replace above function with a static GetTableName function
- Remove verbose comments
- Remove verbose initializers
- Remove need to specify table name when getting a table by name
- Remove unused typedef for mac and linux

* Re-add unused table

Convert tables to singletons

- Convert all CDClient tables to singletons
- Move Singleton.h to dCommon
- Reduce header clutter in CDClientManager

dPhysics/Singleton.h

@@ -1,19 +0,0 @@
-#pragma once
-
-template <typename T>
-class Singleton {
-public:
-	static T& Instance() {
-		static T instance{};
-		return instance;
-	}
-
-	virtual ~Singleton() = default;
-	Singleton(const Singleton& other) = delete;
-	Singleton(Singleton&& other) = delete;
-	Singleton& operator=(const Singleton& other) = delete;
-	Singleton& operator=(Singleton&& other) = delete;
-
-protected:
-	Singleton() = default;
-};