validate the configuration json

[tttp]

we have a few different jsons:

1. campaign config
2. widget config
3. target configs (for mtt)
4. snowflake config (technically part of campaign, but we might want to separate)

campaign and widget have a lot of overlap (journey, component, layout, portals, locales)

https://github.com/colinhacks/zod

seems to be a great one, to be used on the cli tools to validate before generating the widget, not part of the widget

ideally:

1. validating/warning the schema
2. as a documentation (zod can generate it)
3. potentially automatically merge default values with the config used to generate the widget (and simplify the code so instead of having a lot config.component.bla.key ||defaultValue)