Following MDL-65835 this now finally deprecates and removes the
functions:
  - plagiarism_save_form_elements(), please use
    {plugin name}_coursemodule_edit_post_actions() instead
  - plagiarism_get_form_elements_module(), please use
    {plugin name}_coursemodule_standard_elements() instead.
  - plagiarism_plugin::get_form_elements_module(), please
    use {plugin name}_coursemodule_edit_post_actions() instead.
  - plagiarism_plugin::save_form_elements(), please use
    {plugin name}_coursemodule_standard_elements() instead.

Signed-off-by: Daniel Ziegenberg <daniel@ziegenberg.at>