#1441: raise NoMethodError naming the real client for a method it doesn't have

[jack5505]

The client of Fbe.octo is wrapped with intercepted, which calls @o.method(mtd).parameters before the call. For a name the client doesn't have, Kernel#method raises NameError, not NoMethodError, and the message names an anonymous decorator class. A rescue NoMethodError written against Octokit, like the one in lib/qos_search.rb of judges-action, missed it.

The interceptor now checks respond_to? first and raises NoMethodError with the method name and the real client class, Octokit::Client or Fbe::FakeOctokit, the way a plain Octokit client does. Added a test for both clients; it fails without the fix.

Closes #1441