fix #99854 make 'Edit in settings.json' add object-type default

[gjsjohnmurray]

This PR fixes #99854

To test:

1. Clone https://github.com/gjsjohnmurray/vscode-extension-samples/tree/test-vscode-99854
2. Run the modified configuration-sample this branch contains.
3. Open Settings UI.
4. Locate Configuration Samples section under Extensions and click 'Edit in settings.json' link
   
5. After dismissing the automatically-opened quickpick, verify that the defaults for this object-type setting have been inserted:

	"conf.resource.insertEmptyLastLine": {
	
		"one": "FirstDefault",
		"two": {
			"alpha": "abc",
			"number": 123
		}
	}

[gjsjohnmurray]

@sandy081 are you the best person to look at this?