FIX fnx-submit-bar: make FnxForm dependency optional
FIX fnx-submit-bar: make FnxForm dependency optional

So angluar won't complain while trying to instantiate fnx-submit-bar. Fail with more explanatory message, instructing the user how to fix it.

fnx-io/fnx_ui,fnx-io/fnx_ui,fnx-io/fnx_ui,fnx-io/fnx_ui