Reorganized with CodeMaid
Added a new IScope interface and replaced usages of Scope with it.
Added a new IVariableDeclaration interface and replaced usages of VariableDeclaration with it.
Added a new INamedScope interface and replaced usages of NamedScope with it.
Added a new INamespaceDefinition interface and replaced usages of NamespaceDefinition with it.
Added a new ITypeDefinition interface and replaced usages of TypeDefinition with it.