fix(module:time-picker): make keyboard navigation possible

Tabbing away from time-picker overlay was not possible: It wrapped
around and usually ended up in browser's address bar. Also, once you
selected time-picker wrapper span, there was no way to open the overlay
via keyboard.
This fixes this. Tabbing away from overlay now focuses on time-picker
wrapper span. Pressing enter on the wrapper span opens the overlay.

components/time-picker/nz-time-picker.component.html

@@ -6,7 +6,8 @@
   [placeholder]="nzPlaceHolder || ('TimePicker.placeholder' | nzI18n)"
   [(ngModel)]="value"
   readonly="readonly"
-  (click)="open()">
+  (click)="open()"
+  (keyup.enter)="open()">
 <span class="ant-time-picker-icon">
   <i nz-icon nzType="clock-circle"></i>
 </span>
@@ -50,7 +51,9 @@
     [opened]="nzOpen"
     [nzClearText]="nzClearText"
     [nzAllowEmpty]="nzAllowEmpty"
+    (keyup.enter)="close()"
     [(ngModel)]="value">
   </nz-time-picker-panel>
+  <span tabindex="0" (focus)="close()" class="nz-tab-catching-span"></span>
 </ng-template>
 

components/time-picker/nz-time-picker.component.ts

@@ -143,6 +143,7 @@ export class NzTimePickerComponent implements ControlValueAccessor, OnInit, Afte
   close(): void {
     this.nzOpen = false;
     this.nzOpenChange.emit(this.nzOpen);
+    this.focus();
   }
 
   updateAutoFocus(): void {