[BUGFIX] Render custom preview before fluid preview in Page Module

The code that executes the drawItem hook must be called before
the fluid-preview is rendered, in order to allow rendering of custom variables
within the Fluid preview.

This way, it behaves the same way as in the non-Fluidbased page module.

Resolves: #90906
Releases: master
Change-Id: Id7998446b211763da3d3b7be89a4d7016f2fb54f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/64020


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Achim Fritz <af@achimfritz.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Achim Fritz <af@achimfritz.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>