...in 90a326c7 "fdo#61950 move report builder
from bundled extensions to plain code":

* For one, ReportWizard.startReportWizard
(wizards/com/sun/star/wizards/report/ReportWizard.java) would still try to load
reportbuilderwizard.jar from the unpacked extension (and, failing that, fell
back to the old default engine, so this didn't cause any failure per se).
Instead, reference reportbuilderwizard.jar (which was also missing from scp2)
from report.jar's manifest Class-Path (which will always be OK, even if
reportbuilderwizard.jar is not installed) and check for the relevant class via
Class::forName directly.

* For another, the en-US/wizard/report/default.otr template had gone missing.
The way to find it inside the unpacked extension in the past was to include a
Paths.xcu update that extends the Template path.  Instead, install that
template directly into share/template now, and drop the (unused already)
Paths.xcu update.

Change-Id: I09eca2b69aa55d5b15fb5ecfec6881f8a6f6e5e5