Show the extension/source overriding the default value of a setting in settings editor

[sandy081]

With #46851, an extension can override default values of a setting by contributing defaults to contributeDefaults contribution point. Eg:

"configurationDefaults": {
      "workbench.colorTheme": "Monokai"
    }

It would be nice if settings editor can display the source of the default value

CC: @misolori

[sandy081]

@rzhao271 Configuration registry provides you with the source of the default value -

vscode/src/vs/platform/configuration/common/configurationRegistry.ts

Line 205 in 153a028

defaultValueSource?: IExtensionInfo | string;

[miguelsolorio]

I think appending to the end could be a good start:

Monokai default(Extension Name)

[rzhao271]

An issue in this case is that when the extension name is long, there is not enough room to show the source on the right side of that enum option.

Another possible option is to add a codicon next to the setting at the top, where hovering over it would show the extension that overrides the default:

[miguelsolorio]

I think where the "Sync: Ignored" would also be a good option since that is additional meta data. You could do something like: