fix: add VARCHAR2 overloads for DBMS_OUTPUT OUT parameters

Oracle uses VARCHAR2 for GET_LINE and GET_LINES OUT parameters.
When users declare variables as VARCHAR2 (common Oracle practice),
implicit casts don't work for OUT parameters because the value
cannot be written back through the cast.

Add overloaded procedures:
- get_line(line OUT VARCHAR2, status OUT INTEGER)
- get_lines(lines OUT VARCHAR2[], numlines IN OUT INTEGER)

This allows migrated Oracle code using VARCHAR2 to work correctly.

Author: rophy

contrib/ivorysql_ora/expected/ora_dbms_output.out

@@ -646,8 +646,7 @@ BEGIN
     END IF;
 END;
 $$;
-ERROR:  procedure parameter "line" is an output parameter but corresponding argument is not writable
-CONTEXT:  PL/iSQL function inline_code_block line 8 at CALL
+NOTICE:  Test 11.1 - VARCHAR2 GET_LINE: [VARCHAR2 test line]
 -- Test 11.2: GET_LINES with VARCHAR2[] OUT parameter
 DO $$
 DECLARE
@@ -665,8 +664,7 @@ BEGIN
     END IF;
 END;
 $$;
-ERROR:  procedure parameter "lines" is an output parameter but corresponding argument is not writable
-CONTEXT:  PL/iSQL function inline_code_block line 9 at CALL
+NOTICE:  Test 11.2 - VARCHAR2[] GET_LINES: 2 lines
 -- =============================================================================
 -- Cleanup
 -- =============================================================================

contrib/ivorysql_ora/src/builtin_packages/dbms_output/dbms_output--1.0.sql

@@ -78,7 +78,9 @@ CREATE OR REPLACE PACKAGE dbms_output IS
     PROCEDURE put(a TEXT);
     PROCEDURE new_line;
     PROCEDURE get_line(line OUT TEXT, status OUT INTEGER);
+    PROCEDURE get_line(line OUT VARCHAR2, status OUT INTEGER);
     PROCEDURE get_lines(lines OUT TEXT[], numlines IN OUT INTEGER);
+    PROCEDURE get_lines(lines OUT VARCHAR2[], numlines IN OUT INTEGER);
 END dbms_output;
 
 CREATE OR REPLACE PACKAGE BODY dbms_output IS
@@ -116,6 +118,14 @@ CREATE OR REPLACE PACKAGE BODY dbms_output IS
         status := result.status;
     END;
 
+    PROCEDURE get_line(line OUT VARCHAR2, status OUT INTEGER) IS
+        result sys.dbms_output_line;
+    BEGIN
+        SELECT * INTO result FROM sys.ora_dbms_output_get_line();
+        line := result.line;
+        status := result.status;
+    END;
+
     PROCEDURE get_lines(lines OUT TEXT[], numlines IN OUT INTEGER) IS
         result sys.dbms_output_lines;
     BEGIN
@@ -124,4 +134,12 @@ CREATE OR REPLACE PACKAGE BODY dbms_output IS
         numlines := result.numlines;
     END;
 
+    PROCEDURE get_lines(lines OUT VARCHAR2[], numlines IN OUT INTEGER) IS
+        result sys.dbms_output_lines;
+    BEGIN
+        SELECT * INTO result FROM sys.ora_dbms_output_get_lines(numlines);
+        lines := result.lines;
+        numlines := result.numlines;
+    END;
+
 END dbms_output;