Add management of credits

config/config-dev.json

config/config-rec.json

src/app/app.routing.module.ts

...pp/components/credits/detail/credit-detail.component.html

...pp/components/credits/detail/credit-detail.component.scss

src/app/components/credits/detail/credit-detail.component.ts

src/app/components/credits/edit/credit-form.component.html

src/app/components/credits/edit/credit-form.component.scss

src/app/components/credits/edit/credit-form.component.ts

src/app/components/credits/list/credits.component.html

src/app/components/credits/list/credits.component.scss

src/app/components/credits/list/credits.component.ts

src/app/components/index.ts

src/app/components/menu/menu.component.html

src/app/components/menu/menu.component.scss

...ponents/organizations/edit/organization-form.component.ts

src/app/models/credit.model.ts

src/app/models/organization.model.ts

src/app/services/app-config.service.ts

src/app/services/credit.service.ts