Analysis API: rename KtCallableSymbol.type -> returnType

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

@@ -7,8 +7,8 @@ KtValueParameterSymbol:
   name: x
   origin: SOURCE
   receiverType: null
+  returnType: kotlin/Int
   symbolKind: LOCAL
-  type: kotlin/Int
   deprecationStatus: null
 
 KtFunctionSymbol:
@@ -27,11 +27,11 @@ KtFunctionSymbol:
   name: foo
   origin: SOURCE
   receiverType: null
+  returnType: kotlin/Unit
   symbolKind: TOP_LEVEL
-  type: kotlin/Unit
   typeParameters: []
   valueParameters: [
     KtValueParameterSymbol(x)
   ]
   visibility: Public
-  deprecationStatus: null
+  deprecationStatus: null