Add inline helptext for name, add description field, add tests, add migration

[maxtaube]

Description

• adds an inline helptext to the custom alert form name
• adds a description field to custom alert (creation form)
• adds api tests
• adds model updates + migrations
• removes deprecated function call

Issue No

• Fixes #PG-5068

Checklist

• [✔/✖] Tested locally or on demo2/demo3?
• [✔/✖/NA] New test case added/updated?
• [✔/✖/NA] Are all newly added texts included via translation?
• [✔/✖/NA] Are text sanitized properly? (Eg use of v-text v/s v-html for vue)
• [✔] Version bumped?
• [✔] I have understood, reviewed, and tested all AI outputs before use
• [✔] All AI instructions respect security, IP, and privacy rules
• [✔/✖/NA] Documentation updated?