API: Fix namespace handling in list=alldeletedrevs with from/to/predix

We don't have just one namespace like the code we copied this from. And
to avoid a repeat of bug 25702, we have to handle the case where the
title/prefix might be being transformed differently in all the requested
namespaces.

Bug: T75711
Change-Id: I5267847fe876c971aaf358d2c6fe4006e4645939
Merge "API: Fix namespace handling in list=alldeletedrevs with from/to/predix"