add captcha (or similar) to directory listings to reduce spam submissions

[likearecord]

This is a speculative test that we could run to see if it reduces spam. Removal from the directory seems to have helped a small-scale instance with spam issues. We would need to test and see if preventive bot measures, like a captcha, on a larger-org's directory listing would reduce spam submission to the org's instance

Steps:

• Find a large-org who would be willing to test a captcha (or a similar checker) to their directory listing page to mitigate spam
• Solve the self-hosted captcha issue (to avoid leaking data)
• Apply captcha (or similar)
• Check-in with client after 1 month to determine impact