refactor: add plan module

* rename/add plan dirs
* add read plan func/data
* add call plan func/data
* add mutate plan func/data

src/PostgREST/Plan/CallPlan.hs

@@ -0,0 +1,25 @@
+module PostgREST.Plan.CallPlan
+  ( CallPlan(..)
+  , CallParams(..)
+  )
+where
+
+import qualified Data.ByteString.Lazy              as LBS
+import           PostgREST.DbStructure.Identifiers (FieldName,
+                                                    QualifiedIdentifier)
+import           PostgREST.DbStructure.Proc        (ProcParam (..))
+
+import Protolude
+
+data CallPlan = FunctionCall
+  { funCQi           :: QualifiedIdentifier
+  , funCParams       :: CallParams
+  , funCArgs         :: Maybe LBS.ByteString
+  , funCScalar       :: Bool
+  , funCMultipleCall :: Bool
+  , funCReturning    :: [FieldName]
+  }
+
+data CallParams
+  = KeyParams [ProcParam] -- ^ Call with key params: func(a := val1, b:= val2)
+  | OnePosParam ProcParam -- ^ Call with positional params(only one supported): func(val)