[Lists] Trigger field changed when in multiple mode

[joriverm]

Pull Request

📖 Description

autocomplete doesnt trigger the fieldchanged as the default ChangeHandler, which handles the validation/fieldchanged event of the editform, this was fixed by always triggering the event on selection changes for both single and multiple mode.

i also noticed that the list base didnt implement the binding expression property, so the fieldidentifier was always wrong.

🎫 Issues

Fix #3115

👩‍💻 Reviewer Notes

this was tested using the form page from the demo project. i am currently going through the tests to check out if i missed anything

📑 Test Plan

none, i dont see how to put this in a test without adding a binding the bunit test and rendering a validator at the same time. not sure if its worth it?

✅ Checklist

General

• I have added tests for my changes.
• I have tested my changes.
• I have updated the project documentation to reflect my changes.
• I have read the CONTRIBUTING documentation and followed the standards for this project.

Component-specific

• I have added a new component
• I have added Unit Tests for my new component
• I have modified an existing component
• I have validated the Unit Tests for an existing component

⏭ Next Steps

N/A