[TASK] Modernize backend toolbar code

* Use BackendTemplateView
* Hand over template to render as view->render('MyTemplate')
* Move shortcut templates to Toolbar sub folder
* Move LiveSearch JS to Toolbar sub folder
* Shortcut delete and edit are POST only
* Use DI in related controllers and ToolbarItems
* Declare strict_types=1
* Return and property types in PHP classes
* PageRenderer JS module loading via fluid, not PHP
* f:translate with full LLL: keys

Change-Id: Ia8b5ecb312dd83b924955f44f53fb7b3c8415ba3
Resolves: #96519
Related: #96513
Releases: main
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/72996


Tested-by: core-ci <typo3@b13.com>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Tested-by: Benni Mack <benni@typo3.org>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>