Allow picture element options change from twig function

[haivala]

Subject

I am targeting this branch, because this streamlines twig functions for src.

Closes #2342.

Changelog

### Changed
How `picture` element twig options are merged, making them work same way as `srcset`

[VincentLanglet]

Can you add a test about the change ? This will prevent regressions

[haivala]

Can you add a test about the change ? This will prevent regressions

I would need help to do that. I don't know where to begin

[VincentLanglet]

Can you add a test about the change ? This will prevent regressions

I would need help to do that. I don't know where to begin

A unit test need to be added for getHelperProperties in this class
https://github.com/sonata-project/SonataMediaBundle/blob/4.x/tests/Provider/ImageProviderTest.php

You wanted to change the way properties are merged.
So if you call getHelperProperties with a title, prior to this change the title is not used, and now it will.
Write a test to reproduce the behavior you want

• without your change the test fail
• with your change the test succeed

[github-actions]

This PR has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.

[haivala]

I hope this would not be closed.

[VincentLanglet]

I hope this would not be closed.

Feel free to finish it. PR with 6 months inactivity are automatically closed.