printf: this commit adds support for https://github.com/tursodatabase/limbo/issues/885 tracking printf functionality

this commit introduces basic support for printf functionality and doesn't include advanced modifiers like width etc.

testing/scalar-functions-printf.test

@@ -0,0 +1,22 @@
+#!/usr/bin/env tclsh
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+# Basic string formatting
+do_execsql_test printf-basic-string {
+  SELECT printf('Hello World!');
+} {{Hello World!}}
+
+do_execsql_test printf-string-replacement {
+  SELECT printf('Hello, %s', 'Alice');
+} {{Hello, Alice}}
+
+do_execsql_test printf-numeric-replacement {
+  SELECT printf('My number is: %d', 42);
+} {{My number is: 42}}
+
+# Multiple consecutive format specifiers
+do_execsql_test printf-consecutive-formats {
+  SELECT printf('%d%s%f', 1, 'test', 2.5);
+} {{1test2.500000}}