Analysis API: rename KtCallableSymbol.type -> returnType

analysis/analysis-api/testData/symbols/symbolByPsi/topLevelFunctions.txt

@@ -14,8 +14,8 @@ KtFunctionSymbol:
   name: x
   origin: SOURCE
   receiverType: null
+  returnType: kotlin/Int
   symbolKind: TOP_LEVEL
-  type: kotlin/Int
   typeParameters: []
   valueParameters: []
   visibility: Public
@@ -37,9 +37,9 @@ KtFunctionSymbol:
   name: y
   origin: SOURCE
   receiverType: null
+  returnType: kotlin/Unit
   symbolKind: TOP_LEVEL
-  type: kotlin/Unit
   typeParameters: []
   valueParameters: []
   visibility: Public
-  deprecationStatus: null
+  deprecationStatus: null