Upgrading to Angular 20:

Replaced checked in package-lock.json by regenerated one.
Ran ng update @angular/core@20 @angular/cli@20
Ran npm install @angular-builders/jest@^20.0.0 @fortawesome/angular-fontawesome@^3.0.0 @swimlane/ngx-graph@^11
Ran npm install ngx-mat-select-search@^8.0.2.
Ran ng update @angular/material@20.
Updated all eslint and typescript to the latest versions.
Removed @angular-devkit/schematics.
Updated fontawesome.
Updated rxjs and tslib.
Moved required node version from 16 to 20.
Updated jest-preset-angular.
Set preserveWhitespaces to false.
Corrected two type declarations in two typescript files to make ng serve run without errors.
Removed unused angular-devkit/schematics from view-user.component.ts .
Updated list of supported browsers.
Upgraded prettier.
Ran prettier . --write the first time.
Ran prettier . --write the second time.
Ran ng generate @angular/core:inject with defaults, excepted a handful of files.
Fixed remaining eslint problems.
Added dist directory to ignores in eslint.config.js.
Let prettier fix formatting, almost everything is just line breaks.
Made htmlhint ignore @if and @for Angular constructs.
Updated node version in Github workflow to 22.12.0 (build.yml).
Updated .env.ts.
Updated Angular datetime format strings from YYYY-MM-DD to yyyy-MM-dd.
Merged changes from dev into angular20 branch.

src/app/shared/language-selector/language-selector.component.html

@@ -1,8 +1,10 @@
 <mat-form-field id="language-selector" class="m-l-10">
   <mat-label>{{ 'labels.inputs.Language' | translate }}</mat-label>
   <mat-select [formControl]="languageSelector" (selectionChange)="setLanguage()" class="languageselector">
-    <mat-option *ngFor="let language of languages" [value]="language">
-      {{ 'languages.' + language | translate }}
-    </mat-option>
+    @for (language of languages; track language) {
+      <mat-option [value]="language">
+        {{ 'languages.' + language | translate }}
+      </mat-option>
+    }
   </mat-select>
 </mat-form-field>