[BUGFIX] Add a unit to the document size in the adminpanel

There is a "document size" row in the info module of the
adminpanel. Currently the value is outputted as integer, which strips
out its unit. This patch fixes that.

Resolves: #88439
Releases: master, 9.5
Change-Id: I97591bd1799923e5da5604992cd77546bccb1f51
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/60823


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Riccardo De Contardi <erredeco@gmail.com>
Tested-by: Frank Naegler <frank.naegler@typo3.org>
Reviewed-by: Tobi Kretschmann <tobi@tobishome.de>
Reviewed-by: Frank Naegler <frank.naegler@typo3.org>