HCK-11336: fix variant data type conversion to polyglot (#194)

* HCK-11336: fix variant data type conversion to polyglot

* HCK-11336: update convert adapter

Author: serhii-filonenko

polyglot/convertAdapter.json

@@ -76,6 +76,16 @@
 				"to": {
 					"hasMaxLength": true
 				}
+			},
+			{
+				"from": {
+					"type": "variant"
+				},
+				"to": {
+					"type": "binary",
+					"childType": "blob",
+					"mode": "variant"
+				}
 			}
 		]
 	}

types/variant.json

@@ -10,6 +10,7 @@
 		"name": "variant",
 		"jsonRoot": true
 	},
+	"restrictNormalization": true,
 	"defaultValues": {
 		"primaryKey": false,
 		"mode": "var",