[5.0] Move from static Text access to the text function of the plugin

[laoneo]

Summary of Changes

The $this->text() function should be used in plugin template files to translate strings. This eliminates the static use of Text::_. When template files start to use functionality from the current context it will allow them to be reusable.

Testing Instructions

• Create an url custom field
• Open TinyMCE by editing an article
• Check if the strings in the editor buttons are translated

Actual result BEFORE applying this Pull Request

All strings are translated.

Expected result AFTER applying this Pull Request

All strings are translated.

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:

• No documentation changes for manual.joomla.org needed

[richard67]

@laoneo System tests are failing, and I think it could be related to this PR.

[laoneo]

Closing in favor of #41384.