KclvmService.GetSchemaType API: missing default value

[amyXia1994]

Bug Report

Please answer these questions before submitting your issue. Thanks!

1. Minimal reproduce step (Required)

make sure you have konfig repo locally in path , then create a getschema.json file with content(replace the to the real path):

{
    "file": "<path-to-konfig>/base/pkg/kusion_models/kube/frontend/server.k"
}

2. What did you expect to see? (Required)

the property workloadType should have default value: "Deployment"

{
	"error": "",
	"result": {
		"schema_type_list": [
			{
				"type": "schema",
				"schema_name": "Server",
				"schema_doc": "Server is abstaction of Deployment and StatefulSet.",
				"properties": {
					// -- snip --
					"workloadType": {
						"type": "union",
						"union_types": [
							{
								"type": "str(Deployment)"
							},
							{
								"type": "str(StatefulSet)"
							}
						],
						"line": 2,
						"description": "Application workload type, default to 'Deployment'",
						"default": "Deployment"
					}
					// -- snip --
				}// -- snip --
			}
		]
	}
}

3. What did you see instead (Required)

{
	"error": "",
	"result": {
		"schema_type_list": [
			{
				"type": "schema",
				"schema_name": "Server",
				"schema_doc": "Server is abstaction of Deployment and StatefulSet.",
				"properties": {
					// -- snip --
					"workloadType": {
						"type": "union",
						"union_types": [
							{
								"type": "str(Deployment)"
							},
							{
								"type": "str(StatefulSet)"
							}
						],
						"line": 2,
						"description": "Application workload type, default to 'Deployment'"
					}
					// -- snip --
				}// -- snip --
			}
		]
	}
}

4. What is your KCL components version? (Required)

➜  ~ kcl -v
Version: 0.5.3-20ab3eb4b9179219d6837a57f5d35286
Platform: aarch64-apple-darwin
GitCommit: 6481ce567bbad01214f842f7903b5f01ae89324c
➜  ~ kcl-go -v
kcl-go version v0.5.3