Refactor layout and add header, navbar, schedule components

Introduced MainLayoutComponent with header and navbar for consistent app layout. Added HeaderComponent, NavbarComponent, ScheduleComponent, and MainComponent. Updated routing to use MainLayout for main and schedule pages. Renamed home-component to home and main-page to main, removing obsolete main-page files.

src/app/header/header.component.css

@@ -0,0 +1,9 @@
+header {
+  display: flex;
+  width: 100%;
+}
+
+.header {
+  height: 60px;
+  background-color: greenyellow;
+}

src/app/header/header.component.html

@@ -0,0 +1,2 @@
+<header class="header">
+</header>

src/app/header/header.component.ts

@@ -0,0 +1,11 @@
+import { Component } from '@angular/core';
+
+@Component({
+  selector: 'app-header',
+  standalone: false,
+  templateUrl: './header.component.html',
+  styleUrl: './header.component.css'
+})
+export class HeaderComponent {
+
+}