Rename AST structures to Tree and relocate freeing logic

v0/ast/module.h

@@ -13,22 +13,22 @@ typedef struct {
     char* name;
 
     /** @brief The list of imports in the module. */
-    ImportDeclaration* imports;
+    ImportTree* imports;
 
     /** @brief The number of imports in the module. */
     size_t import_count;
 
     /** @brief The list of aliases in the module. */
-    AliasDeclaration* aliases;
+    AliasTree* aliases;
 
     /** @brief The number of aliases in the module. */
     size_t alias_count;
 
     /** @brief The list of variables in the module. */
-    VariableDeclaration* variables;
+    VariableTree* variables;
 
     /** @brief The number of variables in the module. */
     size_t variable_count;
-} Module;
+} ModuleTree;
 
 #endif