Optimize middleware for large datasets

**Feature request**
It would be great to have search for parsers.

**Use case**
Many users need this functionality for production deployments.

**Implementation idea**
Add a new config option `enable_search` with default `false`.

The issue names no files, tests, or entry points. Start by locating the parser middleware and existing configuration handling, then determine the expected search behavior and add coverage for enable_search defaulting to false; the work is done when parser search is available when enabled and unchanged when disabled.

Written by the indexing model from the issue text.