feat: filter top-level resource with embed filter

This is enabled by adding `!inner` to the embedded resource

/projects?select=*,clients!inner(*)&clients.id=eq.12

This behaviour can be enabled by default with the config option

db-embed-default-join='inner'

Which saves the need for specifying `!inner` on every request.
If this is enabled, the previous behavior can be restored
per request by specifying `!left`  on the embedded resource.

/projects?select=*,clients!left(*)&clients.id=eq.12`

Tested on M20/02M/M2M relationships, views, RPC.

test/SpecHelper.hs

@@ -28,6 +28,7 @@ import PostgREST.Config                  (AppConfig (..),
                                           OpenAPIMode (..),
                                           parseSecret)
 import PostgREST.DbStructure.Identifiers (QualifiedIdentifier (..))
+import PostgREST.Request.Types           (JoinType (..))
 import Protolude                         hiding (toS)
 import Protolude.Conv                    (toS)
 
@@ -89,6 +90,7 @@ _baseCfg = let secret = Just $ encodeUtf8 "reallyreallyreallyreallyverysafe" in
   , configDbSchemas             = fromList ["test"]
   , configDbConfig              = False
   , configDbUri                 = mempty
+  , configDbEmbedDefaultJoin    = JTLeft
   , configFilePath              = Nothing
   , configJWKS                  = parseSecret <$> secret
   , configJwtAudience           = Nothing
@@ -125,6 +127,9 @@ testUnicodeCfg testDbConn = (testCfg testDbConn) { configDbSchemas = fromList ["
 testMaxRowsCfg :: Text -> AppConfig
 testMaxRowsCfg testDbConn = (testCfg testDbConn) { configDbMaxRows = Just 2 }
 
+testEmbedInnerJoinCfg :: Text -> AppConfig
+testEmbedInnerJoinCfg testDbConn = (testCfg testDbConn) { configDbEmbedDefaultJoin = JTInner }
+
 testDisabledOpenApiCfg :: Text -> AppConfig
 testDisabledOpenApiCfg testDbConn = (testCfg testDbConn) { configOpenApiMode = OADisabled }