Feature: #90613 - Add language argument to page-related LinkViewHelpers and UriViewHelpers in Fluid

Description

A new argument language is added to the following Fluid ViewHelpers:

<f:link.typolink>
<f:link.page>
<f:uri.typolink>
<f:uri.page>

They are responsible for linking to a page, and are using TypoLink functionality under-the-hood.

Examples

A Link to page with ID 13 but with language 3 - no matter what language the current page is:

<f:link.page pageUid="13" language="3">Go to french version of about us page</f:link.page>

Creating a language menu:

<ul>
  <li>
    <f:link.typolink parameter="current" language="3">Current page in french</f:link.typolink>
  </li>
  <li>
    <f:link.typolink parameter="current" language="4">Current page in german</f:link.typolink>
  </li>
  <li>
    <f:link.typolink parameter="current" language="5">Current page in spanish</f:link.typolink>
  </li>
</ul>

Impact

The new argument allows to force a language when linking to a specific page, making it consistent with the TypoLink option added in site handling for TYPO3 v9:

https://docs.typo3.org/m/typo3/reference-typoscript/main/en-us/Functions/Typolink.html#language

This Fluid option should be used instead of adding a L parameter to additionalParameters argument to make linking to a specific language possible. In general, using of the magic GET variable L is discouraged.