fix: Fix regression in openapi output with mode follow-privileges

This was introduced in d5b92a433a. Before
this change, the OpenApi output would have <pk/> annotations for views,
too. After this change, they got lost for mode follow-privileges, because
the pks are refined in haskell code, but the request only fetches all
the tables again, but not the view dependencies.

This fix changes follow-privileges to only fetch a list of accessible
tables, which is then used to filter the tables in the schema cache.

Fixes #2356

Signed-off-by: Wolfgang Walther <walther@technowledgy.de>

src/PostgREST/SchemaCache/Identifiers.hs

@@ -6,11 +6,13 @@ module PostgREST.SchemaCache.Identifiers
   , Schema
   , TableName
   , FieldName
+  , AccessSet
   , dumpQi
   , toQi
   ) where
 
 import qualified Data.Aeson as JSON
+import qualified Data.Set   as S
 import qualified Data.Text  as T
 
 import Protolude
@@ -40,3 +42,5 @@ toQi txt = case T.drop 1 <$> T.breakOn "." txt of
 type Schema = Text
 type TableName = Text
 type FieldName = Text
+
+type AccessSet = S.Set QualifiedIdentifier