[BUGFIX] Resolve nested TypoScript reference operator

Incoming TS:

lib.foo = TEXT
lib.foo.value = foo
lib.bar =< lib.foo
lib.bar.value = bar
page = PAGE
page.10 = CASE
page.10.key.field = cache_timeout
page.10.default =< lib.foo
page.10.60 =< lib.bar

page.10.60 is a reference to lib.bar which sets the
sub property 'value' to 'bar'. lib.bar itself is a
reference to lib.foo which sets 'TEXT'. When the
cache timeout of a page is set to '60', string 'bar'
should be output.

This stopped working in main since the reference
resolving is not recursive anymore since #99060.

The patch fixes this and adds a unit test to verify.

Resolves: #99504
Related: #97816
Related: #99060
Releases: main
Change-Id: I560807db326559077658b36a61a137fec6cdbcb5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77313


Tested-by: core-ci <typo3@b13.com>
Tested-by: Achim Fritz <af@achimfritz.de>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Reviewed-by: Achim Fritz <af@achimfritz.de>
Tested-by: Stefan Bürk <stefan@buerk.tech>