[5.0] Plugins: load language only when plugin it really needed. Performance optimisation.

[Fedik]

in addittion to #40355 and #40309

Summary of Changes

Most of the plugins wasting a time for loading their language, while it may never used.
I have reviewed some system plugins, and changed $autoloadLanguage to manual loading, on specific event.

It still need some work, but need to wait when #40216 will be merged and upmerged :)

Testing Instructions

Apply patch, make sure the plugins translations 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: IDK
• No documentation changes for docs.joomla.org needed
• Pull Request link for manual.joomla.org: IDK
• No documentation changes for manual.joomla.org needed

[ceford]

I installed German, logged in to Admin with German selected, applied patch and got this:

Die zu ändernde Datei existiert nicht: plugins/system/logrotation/src/Extension/LogRotation.php

Same with English, with Patchtester the patch won't apply - error message:

The file marked for modification does not exist: plugins/system/logrotation/src/Extension/LogRotation.php

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_{This comment was created with the J!Tracker Application at issues.joomla.org/tracker/joomla-cms/40356.}

[brianteeman]

@ceford

[HLeithner]

I merge this since it seems a useful optimization and could be better tested in beta2 and easily fixed or reverted if a translation is missing.

thanks