[BUGFIX] Prevent different constants marker in TS parsing

Currently each time the TypoScript is parsed a new marker for constants,
which are replaces by their value, is generated. This prevents conditions
with replaced constants to be displayed as active. This patch ensures
markers are generated by constants values and therefore stay the same
in different requests.

Resolves: #78142
Related: #72413
Releases: master, 7.6
Change-Id: I4eea83908927ac48930abdd731e7412c04e529c1
Reviewed-on: https://review.typo3.org/50088


Tested-by: TYPO3com <no-reply@typo3.com>
Tested-by: Jasmina Ließmann <code@frauliessmann.de>
Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Nicole Cordes <typo3@cordes.co>
Tested-by: Nicole Cordes <typo3@cordes.co>