[TASK] Rename TreeBuilder to SysTemplateTreeBuilder

We will soon have additional TypoScript TreeBuilder
classes, for instance one related to TsConfig.
Rename the Frontend TypoScript related TreeBuilder
to SysTemplateTreeBuilder to improve namings.

Resolves: #99096
Related: #97816
Releases: main
Change-Id: I32dbd8aae87614d0a2a7d6aaa21e0f71059242a2
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76611


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: Jochen <rothjochen@gmail.com>
Reviewed-by: Jochen <rothjochen@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>