Fix annotation reification for home package modules

The reifyAnnotation method of the Q monad correctly gathered annotations
from TCG and EPS.  Unfortunately it didn't look into the Home Package
Table.  This resulted in annotations not being found if they are in the
same package as the splice that is reifying and ghc --make is used for
compilation management.  Fix this by using the already existing
prepareAnnotations method from HscTypes.lhs that correctly searches
in HPT and EPS both.

Signed-off-by: Austin Seipp <austin@well-typed.com>
Add a comprehensive test for using Annotations from TH

The provided tests test both annotation generation and reification
from Template Haskell.  Both --make and compilation via separate
units (ghc -c) are tested.

Signed-off-by: Austin Seipp <austin@well-typed.com>