[editor] Code cleanup

Use proper types and remove unused vars.

projects/editor/src/app/unit-view/page-view/canvas/canvas.component.ts

@@ -108,8 +108,8 @@ export class CanvasComponent implements OnInit, OnDestroy {
     return this.page.sections.reduce(reduceFct, 0);
   }
 
-  addSection(index: number | null = null): void {
-    this.unitService.addSection(this.page, index);
+  addSection(): void {
+    this.unitService.addSection(this.page);
     this.selectionService.selectedPageSectionIndex = this.page.sections.length - 1;
   }
 

projects/editor/src/app/unit-view/page-view/canvas/section-dynamic.component.ts

@@ -5,6 +5,7 @@ import { CdkDragDrop } from '@angular/cdk/drag-drop/drag-events';
 import { DragItemData, DropListData } from './canvas.component';
 import { UnitService } from '../../../unit.service';
 import { Section } from '../../../../../../common/models/section';
+import { UIElementType } from '../../../../../../common/models/uI-element';
 
 @Component({
   selector: 'app-section-dynamic',
@@ -129,7 +130,7 @@ export class SectionDynamicComponent {
   newElementDropped(event: DragEvent, gridX: number, gridY: number): void {
     event.preventDefault();
     this.unitService.addElementToSection(
-      event.dataTransfer?.getData('elementType') as string,
+      event.dataTransfer?.getData('elementType') as UIElementType,
       this.section,
       { x: gridX, y: gridY }
     );

projects/editor/src/app/unit-view/page-view/canvas/section-static.component.ts

@@ -3,6 +3,7 @@ import {
 } from '@angular/core';
 import { UnitService } from '../../../unit.service';
 import { Section } from '../../../../../../common/models/section';
+import { UIElementType } from '../../../../../../common/models/uI-element';
 
 @Component({
   selector: 'app-section-static',
@@ -33,7 +34,7 @@ export class SectionStaticComponent {
     event.preventDefault();
     const sectionRect = this.sectionElement.nativeElement.getBoundingClientRect();
     this.unitService.addElementToSection(
-      event.dataTransfer?.getData('elementType') as string,
+      event.dataTransfer?.getData('elementType') as UIElementType,
       this.section,
       { x: event.clientX - Math.round(sectionRect.left), y: event.clientY - Math.round(sectionRect.top) }
     );

projects/editor/src/app/unit-view/page-view/new-ui-element-panel/ui-element-toolbox.component.ts

 import { Component } from '@angular/core';
 import { UnitService } from '../../../unit.service';
 import { SelectionService } from '../../../selection.service';
+import { UIElementType } from '../../../../../../common/models/uI-element';
 
 @Component({
   selector: 'app-ui-element-toolbox',
@@ -16,7 +17,7 @@ import { SelectionService } from '../../../selection.service';
 export class UiElementToolboxComponent {
   constructor(private selectionService: SelectionService, public unitService: UnitService) { }
 
-  async addUIElement(elementType: string): Promise<void> {
+  async addUIElement(elementType: UIElementType): Promise<void> {
     this.unitService.addElementToSectionByIndex(elementType,
       this.selectionService.selectedPageIndex,
       this.selectionService.selectedPageSectionIndex);