[!!!][TASK] Remove deprecated code in BackendUtility

Removed the following public methods in the class
\TYPO3\CMS\Backend\Utility\BackendUtility
* getClickMenuOnIconTagParameters
* getUpdateSignalCode

In addition removed usage of `JScode`

Resolves: #101078
Related: #100963
Related: #96136
Releases: main
Change-Id: I395d1cd7db403d1364e7660bd3378e33b03c9624
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79396


Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>