[5.2] Refactor all instances of File::delete() to use framework

[Hackwar]

Summary of Changes

We are in the process of migrating away from the CMS filesystem package to use the framework version of it. This PR converts all instances where File::delete() is used to use the framework version. In that process, all other calls to the CMS File class in that file were converted to properly handle possible exceptions from the framework equivalent. This intentionally did not add additional error handling. I expect that to be a separate effort in the future.

Testing Instructions

Codereview.

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