[5.3] Add the js-grid-item-is-checked class and remove onClick HtmlHelper Grid

[LadySolveig]

Pull Request for Issue # .

Summary of Changes

This PR adds the js-grid-item-is-checked class and remove onClick in the HtmlHelper for Grid as it was originally prepared in the script. https://github.com/joomla/joomla-cms/blob/04d427694b46e9ba9506057723896e1e9aabb9b9/build/media_source/system/js/list-view.es6.js#L99

Testing Instructions

• (optional) install sample data
• go to articles list view
• try out if you can mark single articles bei checkbox and by clicking on the row
• try out if you can mark multiple articles
• try out if you can select and deselect all articles
• try if you can mark articles and use the batch processes

Install this PR Do the same again.

Actual result BEFORE applying this Pull Request

All should work.

Expected result AFTER applying this Pull Request

All should work as before.

Link to documentations

Please select:

• [ ] Documentation link for docs.joomla.org:

• [X] No documentation changes for docs.joomla.org needed

• [ ] Pull Request link for manual.joomla.org:

• [X] No documentation changes for manual.joomla.org needed

[Quy]

I have tested this item :white_check_mark: successfully on 5b16e75b7b0a4c465cc0fdac5bade98dfc5928d6

---

_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/44501.}

[dgrammatiko]

FWIW I had to revert this some time ago as it broke 3rd PD code: https://github.com/joomla/joomla-cms/pull/40192 But would be cool to have CSP strict OOTB at some point