Set responses to uncacheable when the IP address allowlist is matched.

When responses match the IP address allowlist, set the cache control headers to private, to prevent caching proxies from storing the response and potentially serving it to other users.

• Adds a test case for the IP allowlist feature (not sure if there's a better way of mocking the remote IP address).
• Adds logic to set the response to uncacheable if it matched the IP address allowlist.
• Enables page_cache and dynamic_page_cache modules in tests to ensure the logic works with them enabled.

Closes #3525395