Bug 41364: Fix error in preservation module breadcrumb

This patch makes the 'Processings' breadcrum element not be tied to a component but a plain string with the link disabled. This was causing errors:

- Breadcrumb element empty
- Error in the browser console

To test:
1. Enable the Preservation module
2. Go to Home > Preservation > Settings
3. Use the 'Add a new processing' button
=> FAIL: The breadcrumb has 'Settings > > Add processing' (i.e. is missing 'Processings' between >)
4. Click on 'Edit this processing'
=> FAIL: Same error, different context
5. Check the browser console
=> FAIL: You see something like this:

```
[Vue Router warn]: No match found for location with path "/cgi-bin/koha/preservation/settings/processings" devtools-BLCumUwL.mjs:59:1
```

6. Run the cypress tests for this module:
  k$ run_cypress --spec t/cypress/integration/Preservation/Settings.ts
=> FAIL: The breadcrumb navigation is broken
7. Apply this patch
8. Rebuild things:
   $ ktd --shell
  k$ yarn build
9. Fully refresh the page (Use cmd+shift+r on macOS, ctrl+shift+r on Linux/Windows)
10. Repeat 2-6
=> SUCCESS: The breadcrumb is no longer broken
=> SUCCESS: No errors/warnings about this in the browser console
=> SUCCESS: Tests pass!
11. Sign off :-D

Signed-off-by: Tomás Cohen Arazi <tomascohen@theke.io>
Signed-off-by: Lucas Gass <lucas@bywatersolutions.com>
Signed-off-by: David Nind <david@davidnind.com>

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Laura_Escamilla <laura.escamilla@bywatersolutions.com>

koha-tmpl/intranet-tmpl/prog/js/vue/routes/preservation.js

@@ -121,6 +121,8 @@ export const routes = [
                     },
                     {
                         path: "processings",
+                        title: $__("Processings"),
+                        disabled: true,
                         children: [
                             {
                                 path: ":processing_id",