refactor(desktop): organize lib modules by domain

apps/desktop/src/lib/export/databaseExportSelection.ts

@@ -0,0 +1,8 @@
+export function buildSelectedTablesPayload(allTables: string[], selectedTables: string[]): string[] | undefined {
+  if (allTables.length > 0 && selectedTables.length === allTables.length) {
+    return undefined;
+  }
+
+  const selected = new Set(selectedTables);
+  return allTables.filter((table) => selected.has(table));
+}