Corrected property names and structure used in JSON schema generation for configuration of default data to install.

[AndyButland]

Prerequisites

• I have added steps to test this contribution in the description below

Addresses the issue raised here: #17945

Description

As reported in the linked issue, the JSON schema generation for the default data you can configure for install isn't correct.

When merged this PR will ensure that the JSON schema generated is correct and matches the paths used in code. This will correct the intellisense provided when configuring Umbraco.

To Test:

• With the PR merged, rebuild the whole solution.
• Verify the generated schema file found at src\Umbraco.Web.UI\appsettings-schema.Umbraco.Cms.json. You should now see the following elements:

  "InstallDefaultData": {
	  "$ref": "#/definitions/InstallDefaultDataNamedOptions"
  },
		
  "InstallDefaultDataNamedOptions": {
    "type": "object",
    "properties": {
      "Languages": {
        "$ref": "#/definitions/InstallDefaultDataSettings"
      },
      "DataTypes": {
        "$ref": "#/definitions/InstallDefaultDataSettings"
      },
      "MediaTypes": {
        "$ref": "#/definitions/InstallDefaultDataSettings"
      },
      "MemberTypes": {
        "$ref": "#/definitions/InstallDefaultDataSettings"
      }
    }
  },		

• Edit the src\Umbraco.Web.UI\appSettings.json file in an IDE that supports intellisense for configuration, and create an InstallDefaultData element under Umbraco:Cms. Verify the options you are presented with via intellisense match the documented configuration.

[nikolajlauridsen]

Tested with VS code and got intellisens 👍