Replace Willi Wonka and Keith Richards with random typical names

Willi Wonka and Keith Richards are typically not making a good impression to users and they are just two so you can't really show MC features like search, pagination, saved queries etc.

More data = more impressive.

Here's a nice tool that lets you generate typical names for chosen or random cultures for your UI and data samples:

https://uinames.com/

Source Code and Name database: https://github.com/thm/uinames -> MIT license, if we feel more innovative we can generate users on the fly during generation from the names.json
We'll need some sort of user data generator anyways for Cart Sample data!

Choose the cultures we want to address and then generate a bulk per culture and add them as a better data set.

Start by locating how the current Willi Wonka and Keith Richards sample users are defined and how Sunrise data is generated. Review the linked uinames source and its MIT license, then determine the target cultures, generation approach, and sample-data coverage; done means a larger representative dataset that supports meaningful search, pagination, and saved-query demonstrations.

Written by the indexing model from the issue text.