convert help page into standalone component and add lazy loading

pdb-js/src/app/app.module.ts

@@ -6,7 +6,6 @@ import { FormsModule, ReactiveFormsModule } from "@angular/forms";
 
 import { AppRoutingModule } from "./app-routing.module";
 import { AppComponent } from "./app.component";
-import { HelpPageComponent } from "./help-page/help-page.component";
 import { VisualizationPageComponent } from "./visualization-page/visualization-page.component";
 
 import { DatePickerComponent } from "./components/datepicker/date-picker.component";
@@ -59,7 +58,6 @@ import { MainPageComponent } from "./main-page/main-page.component";
 
 @NgModule({ declarations: [
         AppComponent,
-        HelpPageComponent,
         VisualizationPageComponent,
         YAxisDefinitionComponent,
         QueryAutocompleteComponent,