Add new default exception to ignore for Rack::Utils::InvalidParameterError

[dmeranda]

See also similar issue #506

Consider adding the Rack::Utils::InvalidParameterError exception to the built-in list of normally ignored exceptions.

That exception is raised whenever any of the request parameters has an invalid string encoding; such as an invalid UTF-8 byte sequence.

Although invalid strings won't normally be sent by web browsers, it can happen with malware or hacking attacks as a often-used attack vector; so when it does happen these errors can occur rapidly and in large numbers. Bad UTF-8 should probably just result in an HTTP 400 Bad Request response, and little else.

By the way, this UTF-8 checking and exception happens very early in the Rack stack in ActionDispatch::Request.check_param_encoding and can not normally be caught or handled by the Rails application itself, say by a rescue_from.

Steps to reproduce

Use curl, wget, or similar tool other than a web browser, and add an invalid UTF-8 sequence to the end of any application URL; like https://....../example?badstring=%E2%28%A1