Add application settings page

As an administrator, I want a dedicated page to manage all application settings so that I can easily manage application functionality.

Acceptance Criteria:

[x] A new menu item titled "Settings" is added under the "ADMIN" menu
- [x] The new menu item is visible only to users with the "CAN_ADMINISTER_SETTINGS" permission.
[ ] The "Settings" page displays a list of all settings retrieved from the settings options service.
[ ] Settings are grouped by category.
[ ] Each setting displays a text entry field for editing the value with the current value populated.
[ ] Editing a setting triggers a call to the appropriate REST service to save the new value.
[ ] Upon successful saving, a confirmation message is displayed.
[ ] The page reflects the updated settings value after saving.
[ ] Error messages are displayed for any failures.