feat(miniooni): make CLI much more user friendly (#913)

Part of https://github.com/ooni/probe/issues/2184, because I wanted
to allow swapping commands and options more freely.

As a side effect, this PR closes https://github.com/ooni/probe/issues/2248.

AFAICT, every usage that was legal before is still legal. What has
changed seems the freedom to swap commands and options and a much
better help that lists the available options.

internal/cmd/miniooni/main_test.go

@@ -6,7 +6,7 @@ func TestSimple(t *testing.T) {
 	if testing.Short() {
 		t.Skip("skip test in short mode")
 	}
-	MainWithConfiguration("example", Options{
+	MainWithConfiguration("example", &Options{
 		Yes: true,
 	})
 }