[TASK] Add placeholder for title field in create multiple pages

Since the page title field is labeled by "Page X:", instead of
the field label (as it's the case for the doktype), a placeholder
is now added, making the expected value clear to the user.

Resolves: #94525
Releases: master, 10.4
Change-Id: I1c10a0ca5e0954aa5584561e1e4247003a61e61d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69803


Tested-by: core-ci <typo3@b13.com>
Tested-by: Nikita Hovratov <nikita.h@live.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Nikita Hovratov <nikita.h@live.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>