OZG-7473 add validation

...tatistik-fields-form/statistik-fields-form.component.html

.../statistik-fields-form/statistik-fields-form.component.ts

...-mapping-form/statistik-field-mapping-form.component.html

...lib/statistik-fields-form/statistik-fields.formservice.ts

...ech-shared/src/lib/resource/list-resource.service.spec.ts

...ibs/tech-shared/src/lib/resource/list-resource.service.ts

...ch-shared/src/lib/validation/tech.validation.util.spec.ts

...bs/tech-shared/src/lib/validation/tech.validation.util.ts