[TASK] Rename path to extensionmanager module

The URL path to the extensionmanager backend
module is now "/module/tools/extensionmanager"
to be in line with the other "admin tools"
backend modules.

The module identifier is also changed and
a corresponding alias is added.

Resolves: #104156
Releases: main
Change-Id: I140496dcabc29f09b28d276a84a8a96676058898
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84792


Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>