OZG-5977 OZG-7538 add multi upload for bescheid; adjust data-test-id

...e2e/src/components/attachment/attachment.e2e.component.ts

...mponents/vorgang/vorgang-bescheid-wizard.e2e.component.ts

...rgang-bescheid/vorgang-bescheid-dokumente-hochladen.cy.ts

.../apps/alfa-e2e/src/helper/attachment/attachment.helper.ts

alfa-client/apps/alfa-e2e/src/support/data.util.ts

...ile-upload-editor/multi-file-upload-editor.component.html

...form/file-upload-editor/file-upload-editor.component.html

...le-upload-editor/single-file-upload-editor.component.html

...form/file-upload-button/file-upload-button.component.html

...m/file-upload-button/file-upload-button.component.spec.ts

...b/form/file-upload-button/file-upload-button.component.ts