[SECURITY] XSS in belog module

The username of a backend user and title of a workspace record
miss accordant escaping if being rendered in the belog module.

Since this has only impact on admin users in the backend, the
fix is handled in public instead of a security release.

Resolves: #72475
Releases: master, 7.6, 6.2
Change-Id: Ib165f8ef849a641984fc5fb834b30983f7b63a54
Reviewed-on: https://review.typo3.org/45519


Reviewed-by: Markus Klein <markus.klein@typo3.org>
Tested-by: Markus Klein <markus.klein@typo3.org>
Reviewed-by: Morton Jonuschat <m.jonuschat@mojocode.de>
Tested-by: Morton Jonuschat <m.jonuschat@mojocode.de>