Revert "fdo#87044: reportbuilder: Revert "fdo#67930 don't use variables ..."

This reverts commit d6ce95ae2288859fe74d601f1bdaf616ab1ee7f0.

Not necessary to fix fdo#87044, commit
1e10f6d229587ffc2a955c225b489645f8016e23 is sufficient. Since the code
that is reintroduced leads to an overly complex and fragile document
structure, I'd rather not have it.
Revert "reportbuilder: re-add numerous bits of dead code needed by bug fix"

This reverts commit 458f22c338f39ad777ad3f34b45a81b4eb8dfe8e.

Since we reverted d6ce95ae2288859fe74d601f1bdaf616ab1ee7f0, this code
is again unused.