Add custom vendor to managed apps warning messages for delete and upgrade

[momesgin]

Summary

Fixes #13126

Technical notes summary

We already had the warning messages in place, this PR adds the vendor to those messages.

Areas or cases that should be tested

I tested this using the test repo provided by Diogo from the Mapps team:

Git Url: https://github.com/diogoasouza/charts
Branch: test-annotation

First case:

1. Find Istio from the above repo, and install version 105.5.3+up1.24.1(It has catalog.cattle.io/managed set to Flux).
2. Once installed, go to the Installed Apps page and choose Edit/Upgrade from the action menu for rancher-istio.
3. Check if Flux is included in the warning message on the installing page.
4. Go back to the Installed Apps page.
5. Choose Delete from the action menu.
6. Check if Flux is included in the warning message on the modal.

Second case:

1. Go to the Installed Apps page, and find rancher-webhook that is managed by Rancher.
2. Choose Edit/Upgrade from the action menu.
3. Check if Rancher is included in the warning message on the installing page.
4. Go back to the Installed Apps page.
5. Choose Delete from the action menu.
6. Check if Rancher is included in the warning message on the modal.

Areas which could experience regressions

n/a

Screenshot/Video

Checklist

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