UX Consistency Changes to the Pane Header Dropdown Action Menu Labels (instance, holdings, item)

UX Consistency Fix: Update the Action menu labels to follow the latest UX decision and conventions for Pane Header Drop downs to make Inventory aligned with other apps.

Action menus on

1. instance record, then
   • Edit instance is changed to Edit
   • Duplicate instance is changed to Duplicate
2. holdings record, then
   • Edit holdings is changed to Edit
   • Delete holdings record is changed to Delete
   • Duplicate holdings is changed to Duplicate
3. item record, then
   • Edit item is changed to Edit
   • Delete item is changed to Delete
   • Copy item is changed to Duplicate
   • Mark as Missing is changed to Mark as missing
   • New request is changed to be the last action, and not the second last in the list

Document:
The UX consistency and conventions for Pane Header Drop downs be documented in: https://ux.folio.org/docs/guidelines/language-rules/action-language/