[BUGFIX] Correct multi site FE TypoScript caches

The v12 TypoScript parser has a nifty feature to
create the smallest possible amount of cache entries:

When two sys_template records have the same content,
when they're basically just different by their uid,
pid and maybe title, then they share the same
cache entry of their tokenized representation.

A sys_template row that has the "clear constants"
flag set, triggers inclusion of possible site
settings, which are available as constants.

When there are two different sys_template "entry"
records in a multi site instance, those sys_template
records are bound to different sites and should thus
load potentially different site settings. The
data fields of those two sys_template records may be
the same, but still need to trigger different cache
entries. Otherwise, the site settings from the request
that triggered creation of the cache entry swaps into
the other one.

To deal with this scenario, the site identifier of
the current site is now added to the cache identifier,
which leads to different cache entries in this
scenario.

Resolves: #101177
Related: #97816
Related: #99331
Releases: main, 12.4
Change-Id: I4bf9b79fe9e91c8ec7ef01ccffd7661549dc8f86
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/79532


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>