LibSQL: Introduce SELECT ... LIMIT xxx OFFSET yyy

What it says on the tin.

Userland/Libraries/LibSQL/SQLResult.cpp

@@ -0,0 +1,31 @@
+/*
+ * Copyright (c) 2022, Jan de Visser <jan@de-visser.net>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <LibSQL/SQLResult.h>
+
+namespace SQL {
+
+void SQLResult::insert(Tuple const& row, Tuple const& sort_key)
+{
+    m_has_results = true;
+    m_result_set.insert_row(row, sort_key);
+}
+
+void SQLResult::limit(size_t offset, size_t limit)
+{
+    if (offset > 0) {
+        if (offset > m_result_set.size()) {
+            m_result_set.clear();
+            return;
+        }
+        m_result_set.remove(0, offset);
+    }
+    if (m_result_set.size() > limit) {
+        m_result_set.remove(limit, m_result_set.size() - limit);
+    }
+}
+
+}