Add db-extra-search-path config (#1218)

For adding schemas to the search_path, solves issues related to extensions created in the public schema.

test/Feature/ExtraSearchPathSpec.hs

@@ -0,0 +1,37 @@
+module Feature.ExtraSearchPathSpec where
+
+import Test.Hspec
+import Test.Hspec.Wai
+import Test.Hspec.Wai.JSON
+import Network.HTTP.Types
+
+import SpecHelper
+import Network.Wai (Application)
+
+import Protolude
+
+spec :: SpecWith Application
+spec = describe "extra search path" $ do
+
+  it "finds the ltree <@ operator on the public schema" $
+    request methodGet "/ltree_sample?path=cd.Top.Science.Astronomy" [] ""
+      `shouldRespondWith` [json|[
+        {"path":"Top.Science.Astronomy"},
+        {"path":"Top.Science.Astronomy.Astrophysics"},
+        {"path":"Top.Science.Astronomy.Cosmology"}]|]
+      { matchHeaders = [matchContentTypeJson] }
+
+  it "finds the ltree nlevel function on the public schema, used through a computed column" $
+    request methodGet "/ltree_sample?select=number_of_labels&path=eq.Top.Science" [] ""
+      `shouldRespondWith` [json|[{"number_of_labels":2}]|]
+      { matchHeaders = [matchContentTypeJson] }
+
+  it "finds the isn = operator on the extensions schema" $
+    request methodGet "/isn_sample?id=eq.978-0-393-04002-9&select=name" [] ""
+      `shouldRespondWith` [json|[{"name":"Mathematics: From the Birth of Numbers"}]|]
+      { matchHeaders = [matchContentTypeJson] }
+
+  it "finds the isn is_valid function on the extensions schema" $
+    request methodGet "/rpc/is_valid_isbn?input=978-0-393-04002-9" [] ""
+      `shouldRespondWith` [json|true|]
+      { matchHeaders = [matchContentTypeJson] }