Move notebooks to workbench (#4888)

* move notebooks under workbench

* fix style imports

src/sql/workbench/parts/notebook/cellViews/placeholderCell.component.ts

@@ -0,0 +1,85 @@
+/*---------------------------------------------------------------------------------------------
+*  Copyright (c) Microsoft Corporation. All rights reserved.
+*  Licensed under the Source EULA. See License.txt in the project root for license information.
+*--------------------------------------------------------------------------------------------*/
+import 'vs/css!./placeholder';
+
+import { OnInit, Component, Input, Inject, forwardRef, ElementRef, ChangeDetectorRef, OnDestroy, ViewChild, SimpleChange, OnChanges } from '@angular/core';
+import { CellView } from 'sql/workbench/parts/notebook/cellViews/interfaces';
+import { ICellModel } from 'sql/workbench/parts/notebook/models/modelInterfaces';
+import { NotebookModel } from 'sql/workbench/parts/notebook/models/notebookModel';
+import { localize } from 'vs/nls';
+import { CellType } from 'sql/workbench/parts/notebook/models/contracts';
+
+
+export const PLACEHOLDER_SELECTOR: string = 'placeholder-cell-component';
+
+@Component({
+	selector: PLACEHOLDER_SELECTOR,
+	templateUrl: decodeURI(require.toUrl('./placeholderCell.component.html'))
+})
+
+export class PlaceholderCellComponent extends CellView implements OnInit, OnChanges {
+	@Input() cellModel: ICellModel;
+	@Input() set model(value: NotebookModel) {
+		this._model = value;
+	}
+
+	private _model: NotebookModel;
+
+	constructor(
+		@Inject(forwardRef(() => ChangeDetectorRef)) private _changeRef: ChangeDetectorRef,
+	) {
+		super();
+	}
+
+	ngOnInit() {
+		if (this.cellModel) {
+			this._register(this.cellModel.onOutputsChanged(() => {
+				this._changeRef.detectChanges();
+			}));
+		}
+	}
+
+	ngOnChanges(changes: { [propKey: string]: SimpleChange }) {
+	}
+
+	get model(): NotebookModel {
+		return this._model;
+	}
+
+	get clickOn(): string {
+		return localize('clickOn','Click on');
+	}
+
+	get plusCode(): string {
+		return localize('plusCode', '+ Code');
+	}
+
+	get or(): string {
+		return localize('or', 'or');
+	}
+
+	get plusText(): string {
+		return localize('plusText', '+ Text');
+	}
+
+	get toAddCell(): string {
+		return localize('toAddCell', 'to add a code or text cell');
+	}
+
+	public addCell(cellType: string, event?: Event): void {
+		if (event) {
+			event.stopPropagation();
+		}
+		let type: CellType = <CellType>cellType;
+		if (!type) {
+			type = 'code';
+		}
+		this._model.addCell(<CellType>cellType);
+	}
+
+	public layout() {
+
+	}
+}