Consolidate Puma low-level error handler code

What does this MR do and why?

Previously the Puma low-level error handler was specified in three different places (Cloud Native GitLab, Omnibus GitLab, GitLab Development Kit). Any time a change was needed we would have to update three different files. We can simplify this by putting in a central class that each of the configuration files can use.

Relates to #426135 (closed)

How to set up and validate locally

1. Check out this branch.
2. In your GDK directory, checkout gitlab-development-kit!3373 (merged).
3. Run bundle exec rake gitlab/config/puma.rb from the GDK directory.
4. gdk restart rails-web
5. Then attempt to submit an invalid URL to trigger the low-level handler:

$ curl -I 'http://gdk.test:3000/-/merge_requests?sort=created_date&state=<th:t=\"%24{dfb}%23foreach'
HTTP/1.1 400 Bad Request
Date: Mon, 25 Sep 2023 14:41:36 GMT

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