Feature: #86057 - Improved typolink / URL link generation

Description

With new site-based handling, the de-facto standard GET parameter "L" (for language) became obsolete.

Instead, in order to create a link to a specific language via TypoScript's typolink functionality, a new parameter typolink.language is introduced.

page.10 = TEXT
page.10.value = Link to the page with the ID in the current language
page.10.typolink.parameter = 23
page.20 = TEXT
page.20.value = Link to the page with the ID in the language 3
page.20.typolink.parameter = 23
page.20.typolink.language = 3

Omitting the parameter language will use the current language. If a page is not available in the requested language, the link will not be generated, however a fallback to the default language can be built, as the HMENU TypoScript functionality does.

Due to the new page-linking functionality, the following TypoScript settings are not necessary anymore and should be removed for TypoScript configurations on page trees with a site configuration:

• Including the "L" parameter in config.linkVars, as the L parameter is not evaluated for page requests with a site configuration.
• config.absRefPrefix is only necessary for links to files or images, but not for page links, as they are always built against the absolute path, or - if typolink.forceAbsoluteUrl is explicitly set. The option is set to auto by default for site configuration TypoScripts, so this is not necessary anymore in regular installations.
• One of the major strengths allows to link across sites / domains with specifically knowing all available languages of a different page tree. Using the config.typolinkEnableLinksAcrossDomains is not necessary anymore for TypoScript within a site configuration.

Impact

When using typolink.additionalParams = &L=1, this is automatically mapped to the typolink.language parameter, but if both are set, the typolink.language option takes precedence.

When generating links with &L= query parameters, this parameter is stripped, and the correct base URL for the site is fetched, and the query parameter is not added anymore.

By setting the target page ID via typolink.parameter it is also possible to set the page ID to a localized page ID, automatically resolving to the correct language if neither typolink.parameter nor typolink.additionalParams = L= is set.