GN-5187: add clearer warning to mandatee table on losing changes

[elpoelma]

Overview

This PR includes two adjustments to the synchronisation warning shown in mandatee table nodes:

• The message is now clearer/more correct
• The message is now shown in a yellow AuAlert component

connected issues and PRs:

GN-5187

Setup

None

How to test/reproduce

• Start the dummy app
• Open the 'Besluit sample' page
• Insert a mandatee table
• The sync warning should be clearer in terms of message as well as visibility

Checks PR readiness

• UI: works on smaller screen sizes
• UI: feedback for any loading/error states
• Check if dummy app is correctly updated
• Check cancel/go-back flows
• changelog
• npm lint
• no new deprecations