[FEATURE] Show link to online docs in extension manager

The export of extensions provided by https://extensions.typo3.org
has been extended with the link to the documentation.

This link is now shown in the list and detail view of extensions
in the extensions manager.

Resolves: #89458
Releases: master
Change-Id: If1439bd7b97d9c60c2811716edef97a6e4ed870d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/62032


Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Benni Mack <benni@typo3.org>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Benni Mack <benni@typo3.org>