Delete old, unused metadata component

src/main/webapp/app/search/metadata/metadata-message.service.ts

-// unused
-/*
-// The code in this file and the files using this file is partially taken from
-// https://stackoverflow.com/questions/46487255/pass-observable-data-from-parent-component-to-a-child-component-created-with-com
-import { Injectable } from '@angular/core';
-import { Subject, Observable } from 'rxjs';
-import { IMetadataSelection, MetadataSelection } from 'app/search/metadata/metadata-selection.component';
-
-@Injectable()
-export class MetadataMessageService {
-  filterSelection$: Observable<IMetadataSelection>;
-  private filterSelectionSubject: Subject<IMetadataSelection> = new Subject<IMetadataSelection>();
-
-  constructor() {
-    this.filterSelection$ = this.filterSelectionSubject.asObservable();
-  }
-
-  public updateFilterSelection(metadataCategory: string, value: string): void {
-    this.filterSelectionSubject.next(new MetadataSelection(metadataCategory, value));
-  }
-}
-*/

src/main/webapp/app/search/metadata/metadata-selection.component.ts

-// unused
-/*
-export interface IMetadataSelection {
-  category: string;
-  value: string;
-}
-
-export class MetadataSelection implements IMetadataSelection {
-  constructor(public category: string, public value: string) {}
-}
-*/

src/main/webapp/app/search/metadata/metadata.component.html

-<div class="solid" [hidden]="frequencies == null">
-    <span class="meta" jhiTranslate="search.metadata.{{parameter}}">file format</span>
-    <span class="clear" float="right" jhiTranslate="search.metadata.clearLocalFilters"
-        (click)="clearFilters()">clear all</span>
-    <li class="unselected" *ngFor="let frequency of frequencies"
-        (click)="toggleSelection(frequency.key)"
-        [ngClass]="isSelected(frequency.key) ? 'selected' : 'unselected'">
-        <div>
-            <a class="meta">{{frequency.key}}
-                <span class="count">{{frequency.value}}</span>
-            </a>
-        </div>
-    </li>
-</div>

src/main/webapp/app/search/metadata/metadata.component.ts

-// unused
-/*
-import { Component, Input } from '@angular/core';
-import { IFrequency } from 'app/shared/model/frequency.model';
-import { MetadataMessageService } from 'app/search/metadata/metadata-message.service';
-
-@Component({
-  selector: 'jhi-home-metadata',
-  templateUrl: './metadata.component.html',
-  styleUrls: ['./metadata.scss'],
-})
-export class MetadataComponent {
-  @Input() frequencies!: IFrequency<string>[] | undefined;
-  @Input() parameter!: string;
-
-  testString = '';
-  selectedItems = new Set<string>();
-
-  constructor(public messageService: MetadataMessageService) {}
-
-  toggleSelection(name: string): void {
-    this.messageService.updateFilterSelection(this.parameter, name);
-    if (this.selectedItems.has(name)) {
-      this.selectedItems.delete(name);
-    } else {
-      this.selectedItems.add(name);
-    }
-  }
-
-  isSelected(name: string): boolean {
-    return this.selectedItems.has(name);
-  }
-
-  clearFilters(): void {
-    for (const selectedItem of this.selectedItems) {
-      this.messageService.updateFilterSelection(this.parameter, selectedItem);
-    }
-    this.selectedItems = new Set<string>();
-  }
-}
-*/

src/main/webapp/app/search/metadata/metadata.scss

-// unused
-/*
-li.meta:hover {
-  background-color: #cacaca;
-}
-li.meta {
-  list-style-type: none;
-  padding-left: 20px;
-  padding-right: 20px;
-}
-a.meta {
-  font-weight: normal;
-}
-span.meta {
-  font-weight: bold;
-  margin-bottom: 50px;
-}
-span.count {
-  float: right;
-}
-div.solid {
-  border-style: solid;
-  border-width: 1pt;
-  padding: 10px;
-  border-color: rgb(223, 226, 230);
-  margin-bottom: 20px;
-}
-span.clear {
-  float: right;
-  padding-left: 10px;
-  padding-right: 10px;
-  cursor: pointer;
-  font-size: 0.9em;
-}
-span.clear:hover {
-  background-color: rgba(0, 0, 0, 0.1);
-}
-li.selected {
-  list-style-type: none;
-  padding-left: 20px;
-  padding-right: 20px;
-  background-color: rgb(200, 200, 200);
-}
-li.unselected {
-  list-style-type: none;
-  padding-left: 20px;
-  padding-right: 20px;
-}
-*/