[BUGFIX] Prioritize form default values over TCA overrides

When defining a default value in column overrides
e.g. for tt_content TCA field sys_language_uid
this value from TCA will override the value that will
be set via the page module when adding a content
element for a different language, because the change
introduced in #86876 does not respect default values
that are set via defVals (which are passed to form engine
as defaultValues)

A check if such values are set is now added, so that
the fix for #86876 will still work, but default values set
via editing forms are also respected

Resolves: #99381
Releases: main, 11.5
Change-Id: Ib4270665b396bbe520afb21a7f145d0d549305ac
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/78893


Tested-by: core-ci <typo3@b13.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Oliver Bartsch <bo@cedev.de>