Allow multiple schemas to be exposed in one instance (#1450)

The schema to use can be selected through the headers `Accept-Profile` for GET/HEAD and `Content-Profile` for POST/PATCH/PUT/DELETE.

This is based on the https://www.w3.org/TR/dx-prof-conneg/ttps://www.w3.org/TR/dx-prof-conneg/ spec.

Also increase all memory tests by 1M(otherwise CI fails).

Co-authored-by: Mahmoud Kassem <MKassem@gk-software.com>
Co-authored-by: Mahmoud Kassem <mahmoud_k@mail.com>

test/Feature/JsonOperatorSpec.hs

@@ -7,7 +7,7 @@ import Test.Hspec
 import Test.Hspec.Wai
 import Test.Hspec.Wai.JSON
 
-import PostgREST.Types (PgVersion, pgVersion112)
+import PostgREST.Types (PgVersion, pgVersion112, pgVersion121)
 import Protolude       hiding (get)
 import SpecHelper
 
@@ -26,7 +26,12 @@ spec actualPgVersion = describe "json and jsonb operators" $ do
 
     it "fails on bad casting (data of the wrong format)" $
       get "/complex_items?select=settings->foo->>bar::integer"
-        `shouldRespondWith` [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
+        `shouldRespondWith` (
+        if actualPgVersion >= pgVersion121 then
+        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for type integer: \"baz\""} |]
+        else
+        [json| {"hint":null,"details":null,"code":"22P02","message":"invalid input syntax for integer: \"baz\""} |]
+                            )
         { matchStatus  = 400 , matchHeaders = [] }
 
     it "obtains a json subfield two levels (string)" $