Add initial data creation

[jsangmeister]

fixes OpenSlides/OpenSlides#6745

See OpenSlides/openslides-datastore-service#245 (comment) for additional context.

Also fixed some types and interface usages.

During startup of the action container, it checks now if the env var OPENSLIDES_BACKEND_CREATE_INITIAL_DATA ist set. In that case, the initial data file is read and send to the action organization.initial_import.

[r-peschke]

LGTM

[peb-adr]

This will leave the superadmin (user/1) unusable as no password is defined in https://github.com/OpenSlides/openslides-backend/blob/main/global/data/initial-data.json.\
There shouldn't be one defined either IMO as it would pose a security risk as people may start using the same default password for the superadmin.

The initial-data manage command currently will fire a user.set_password action after the initial import to set the generated password from the secrets/superadmin file.
So the code should be expanded to check for $SUPERADMIN_PASSWORD_FILE (default: /run/secrets/superadmin) and if it exists set superadmin's password to it's content.

[jsangmeister]

@peb-adr I added the password setting as described. I renamed the variable to OPENSLIDES_BACKEND_SUPERADMIN_PASSWORD_FILE to conform with the other backend variables, I hope that's okay.

I also changed the setup slightly to load the example data file in test mode instead of the initial data. This is currently also the case and should not change, since it would make life harder for client developers.

[jsangmeister]

@r-peschke I adjusted the test setup slightly to make it easier to access application class specific attributes, e.g. the logger. Maybe you can use the same adjustments for your tests in #2335

[peb-adr]

@peb-adr I added the password setting as described. I renamed the variable to OPENSLIDES_BACKEND_SUPERADMIN_PASSWORD_FILE to conform with the other backend variables, I hope that's okay.

Tbh I would prefer it stays as is.
I think should not conform with the other backend variables but rather the other secret path variables.
See https://github.com/OpenSlides/openslides-manage-service/blob/ac17d372845d464740b9c9ac43a42bbfc898faf8/pkg/config/default-config.yml#L76

[jsangmeister]

Tbh I would prefer it stays as is. I think should not conform with the other backend variables but rather the other secret path variables. See https://github.com/OpenSlides/openslides-manage-service/blob/ac17d372845d464740b9c9ac43a42bbfc898faf8/pkg/config/default-config.yml#L76

Sure, I also see that, renamed it