fix: 284 collection code input field allow letters

https://issues.unige.ch/browse/AOU-284

src/app/features/deposit/components/presentationals/deposit-form-description-collection/deposit-form-description-collection.presentational.html

@@ -23,7 +23,8 @@
     >
       <mat-label>{{labelTranslateEnum.code | translate}}</mat-label>
       <input matInput
-             type="number"
+             min="1"
+             step="1"
              [solidifyValidation]="errors"
              [formControl]="fd"
              [required]="formValidationHelper.hasRequiredField(fd)"