Currently, the basic and demo data seeds are not (fully) localized, even though we could simply let them be translated by crowdin.

#### Acceptance criteria

* Seeding of an OpenProject installation's data is supported in all the languages configured on Crowdin.
* Upon the first configuration of the installation, the `default_language` setting is queried for:
* packaged installation: part of the wizard (before the seeding)
* docker: Providable as an environment variable
* kubernetes: Providable as an environment variable
* When seeding, the `default_language` determines the locale in which the seeding is carried out.

#### Possibly in scope

* Creation of SaaS tenants with localized seed data
* Initial users selects locale as part of the tenant creation process.
* \[technical\] tenant databases of supported locales are produced and stockpiled and the appropriate database is then assigned based on the locale.

#### Out of scope

* Changes to the seeded data structure are out of scope. The same data as before will be seeded. Begin of the insertion
* Translating text in image attachments.End of the insertion