OZG-5012 move resource service creation/configuration to module

...admin-settings/src/lib/admin-settings-resource.service.ts

...ient/libs/admin-settings/src/lib/admin-settings.module.ts

...ibs/admin-settings/src/lib/admin-settings.service.spec.ts

...ent/libs/admin-settings/src/lib/admin-settings.service.ts

...s/src/lib/configuration/configuration-resource.service.ts

...tings/src/lib/configuration/configuration.service.spec.ts

...n-settings/src/lib/configuration/configuration.service.ts

...in-settings/src/lib/postfach/postfach-resource.service.ts

.../libs/admin-settings/src/lib/postfach/postfach.service.ts

alfa-client/libs/bescheid-shared/src/lib/bescheid.service.ts