Set the page position for `post-details` to always start at the very top OnInit

[esthersoftwaredev]

Describe the solution you'd like

• angular takes previous page position
• adjust post-details so that the content is loading from the very top and you are not lower on the y-index of the page
• to be implemented within the OnInit lifecycle in the post-details component
• using the ViewportScroller see implementatinon here

[DongreJaipal]

.take