Makes module name a required field.

- Adds required to the formSubmit method call to prevent
  modules from being created with blank names.

fixes CNVS-14931

Test Plan:
  - Using screenreader/keyboard-only navigation
  - Go to the modules page (/courses/##/modules)
  - Press enter on the "Create a Module" button
  - A module should not be created without a name, and
    the dialog should stay open.

Change-Id: I81b8a8c3557583e50f3058b1c643324659a1c1f2
Reviewed-on: https://gerrit.instructure.com/40276
Reviewed-by: Ryan Shaw <ryan@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Tested-by: Jenkins <jenkins@instructure.com>
Product-Review: Cosme Salazar <cosme@instructure.com>