W33 Fixes

Changes:

• Fixed empty Unit List when synonym wasn't used and attribute field changed.
• Added navigation buttons at the top of forms.
• Fixed Notices:
  • Undefined index: data_type in tpps_add_buttons() (line 751 of .../TGDR/includes/form_utils.inc).
  • Fixed notices about missing variables when page 3 validation started.
  • notices about missing optional variables 'states', 'extra_elements' in tpps_genotype_build_file_field().
  • Undefined variable: empty_field_value in tpps_genotype_build_file_field() (line 1916 of .../TGDR/forms/build/page_4_helper.php).
  • Notices about missing variables at page 4.
• Removed (but not fixed) spam message: Notice: Undefined variable: show_nafgs_menu in include() (...themes/dawn/tpl/page.tpl.php).

Task: https://app.clickup.com/t/861n7bkh4