ReadQuery: split out to fix record field warning

The use of `where_` in DbRequestBuilder issues a warning since
GHC 9.2 as per
https://github.com/ghc-proposals/ghc-proposals/blob/master/proposals/0366-no-ambiguous-field-access.rst

To disambiguate that, move the type to a separate module and use
the record field names qualified. For symmetry, MutateQuery also
gets its own module.

src/PostgREST/Query/QueryBuilder.hs

@@ -28,7 +28,9 @@ import PostgREST.DbStructure.Relationship (Cardinality (..),
 import PostgREST.Request.Preferences      (PreferResolution (..))
 
 import PostgREST.Query.SqlFragment
-import PostgREST.RangeQuery        (allRange)
+import PostgREST.RangeQuery          (allRange)
+import PostgREST.Request.MutateQuery
+import PostgREST.Request.ReadQuery
 import PostgREST.Request.Types
 
 import Protolude