[bug][34041] JToolbar Popup button modal icon class not customizable. Fixes #4075
[imp][34026] Improved search functionality in list views. Closes #4051
[cs] Use $this->params instead $app->getTemplate(true)->params at the templates. Closes #3930
Revert "[cs] Use $this->params instead $app->getTemplate(true)->params at the templates. Closes #3930"

This reverts commit fe2509e1eb1fcf053fcd958392e447ee3b5d1ef2.

For some reason, this doesn't work in the error page.
code style