chore(agent): use notification message to patch template table

[tthvo]

Welcome to Cryostat! 👋

Before contributing, make sure you have:

• Read the contributing guidelines
• Linked a relevant issue which this PR resolves
• Linked any other relevant issues, PR's, or documentation, if any
• Resolved all conflicts, if any
• Rebased your branch PR on top of the latest upstream main branch
• Attached at least one of the following labels to the PR: [chore, ci, docs, feat, fix, test]
• Signed the last commit: git commit --amend --signoff

---

Fixes: #586
Depends on https://github.com/cryostatio/cryostat/pull/1273

Description of the change:

This change clean up notification handling in the AgenTemplate table to use notification message and patch the table without refreshing.

Motivation for the change:

• Avoid unncessary api requests and allow smoother UI.
• Upload modal is uncessarily unmounted due to refeshing causes loading view to render. This fix will avoid this, allowing the modal to keep local states (to display failed files).

How to manually test:

1. Start the backend with latest changes from https://github.com/cryostatio/cryostat/pull/1273. For example:

   $ CRYOSTAT_IMAGE=ghcr.io/cryostatio/cryostat:pr-1273-254d0939d87cfa7940d734311b06d959f58d7cdc sh smoketest.sh
   

2. Delete or add templates.
3. All functionality should remain the same.
4. UI should not enter loading state if agent-template-related notifications are received.

[github-actions]

This PR/issue depends on:

• cryostatio/cryostat#1273
  By Dependent Issues (🤖). Happy coding!

[maxcao13]

Looks good, renders nicely and notification handles correctly. :)