Audit and minimize use of last major indirect method: search()

Audit and minimize use of last major indirect method: search()

I am not entirely sure how I missed it during 1b822bd3, but oh well. This
should be the last highly volatile part ( as far as downstream is concerned ).

As previously - zero functional changes apart from no longer calling search()
at several spots (the SanityChecker ensures none of this results in silent
breakage)

All spots that *do* require wantarray()-specific behavior remained explicit
wrappers for search(), instead of doing the wantarray() check themselves: this
is a deliberate choice to allow DBIC::Helpers::ResultSet::IgnoreWantarray or
similar libraries to continue operating by simply hooking the search() method