feat: Configuration for sub generators tiles in Template Wizard

[GDamyanov]

This PR is just a POC for showing sub generators tiles in Template Wizard.
If you want to show tile for sub generator you should add the following configuration in the package.json if the main generator:
"additional_generators": [ { "namespace": "@sap/adaptation-project:adaptation-project", "displayName": "Sub Generator Tile", "description": "Sub generator description" } ]

• namespace value should be the namespace of the sub generator.
• displayName is used for the name in the tile
• description is used for the description in the tile

We can add also properties for tile icon and tile additional info

[cla-assistant]

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