OZG-7473 use getter and rename file

...eld-form/aggregation-mapping-field-form.component.spec.ts

...ng-field-form/aggregation-mapping-field-form.component.ts

...orm/aggregation-mapping-field-list-form.component.spec.ts

...ist-form/aggregation-mapping-field-list-form.component.ts

...n-mapping-form/aggregation-mapping-form.component.spec.ts

...gation-mapping-form/aggregation-mapping-form.component.ts

...tion-mapping-form/aggregation-mapping.formservice.spec.ts

...gregation-mapping-form/aggregation-mapping.formservice.ts