LibJS: Drop "Record" suffix from all the *Environment record classes

"Records" in the spec are basically C++ classes, so let's drop this
mouthful of a suffix.

Userland/Libraries/LibJS/Forward.h

@@ -120,16 +120,16 @@ class BoundFunction;
 class Cell;
 class CellAllocator;
 class Console;
-class DeclarativeEnvironmentRecord;
+class DeclarativeEnvironment;
 class DeferGC;
-class EnvironmentRecord;
+class Environment;
 class Error;
 class ErrorType;
 class Exception;
 class Expression;
-class FunctionEnvironmentRecord;
+class FunctionEnvironment;
 class FunctionNode;
-class GlobalEnvironmentRecord;
+class GlobalEnvironment;
 class GlobalObject;
 class HandleImpl;
 class Heap;
@@ -138,7 +138,7 @@ class Interpreter;
 class MarkedValueList;
 class NativeFunction;
 class NativeProperty;
-class ObjectEnvironmentRecord;
+class ObjectEnvironment;
 class PrimitiveString;
 class PromiseReaction;
 class PromiseReactionJob;