Fix: Preserve submit button value in form submissions with custom events

[iraprabhu05]

Changes

Fixes incorrect event name parsing in custom-events.js for issue #5050.
Added proper handling so custom events trigger correctly with updated tracking logic.

Tests

• Automated tests have been added
• This PR does not require tests

Changelog

• Entry has been added to changelog
• This PR does not make a user-facing change

Documentation

• Docs have been updated
• This change does not need a documentation update

Dark mode

• The UI has been tested both in dark and light mode
• This PR does not change the UI

[iraprabhu05]

Hi, bringing this up in case it got missed. The checks are still awaiting approval and I’m happy to make any required updates.

[ukutaht]

Hey! Sorry about the wait. This has been a long-standing bug in our tracker and I'm glad you've proposed a fix. Thank you! 🙏

The tracker code has pretty extensive test coverage and this feels like something that should be tested as well. To move forward there's 2 options:

1. If you add a test in this PR, I'll happily merge
2. Otherwise we'll commit to doing it ourselves but it means it will probably take some time until the current backlog is cleared and we find time focus on it

[iraprabhu05]

Hi! I’ve added the test you requested.

It verifies that the submit button’s value is preserved when forms are submitted with custom events, and confirms that the expected payload includes the correct provider value. Everything now aligns with the expected behavior from the issue.

Happy to update anything further if needed, and thank you for the clear feedback!

[CLAassistant]

All committers have signed the CLA.

[ukutaht]

@iraprabhu05 I've approved the workflows. The test is failing and there's a formatting issue

[ukutaht]

Test needs to be fixed