[5.2] Deprecate HTMLHelper::script(), HTMLHelper::stylesheet(), extend lifetime for Document style/script methods

[Fedik]

Pull Request for Issue # .

Summary of Changes

Deprecate HTMLHelper::script(), HTMLHelper::stylesheet().
Extend lifetime for Document style/script methods, because they cannot be removed before HTMLHelper::script(), HTMLHelper::stylesheet().

Add a new method HTMLHelper::mediaPath(), because we still need to lookup for overides.
Kind of temporary solution, until someone will come up with improvements to our media override API.

Testing Instructions

Apply patch. Make sure all works as before.

Add media/templates/administrator/atum/css/user.css to atum template, and make sure it still works.

Actual result BEFORE applying this Pull Request

Works

Expected result AFTER applying this Pull Request

Works

Link to documentations

Please select:

• Documentation link for docs.joomla.org:
• No documentation changes for docs.joomla.org needed
• Pull Request link for manual.joomla.org: TBD
• No documentation changes for manual.joomla.org needed