Enforce query instance checking before it wrapper as a filter

We have the default QueryWrapperFilter as well as our custom one while
our wrapper is explicitly marked as no_cache such that it will never
be included in a cache. This was not consistenly used and caused several
problems during tests where p/c related queries were used as filters
and ended up in the cache. This commit adds the QueryWrapperFilter
ctor to the forbidden APIs to enforce the query instance checks.
Improve exception handling in HttpDownloadHelper