Allow client side #fragments (e.g. anchor links) for pagination links

Problem/Motivation

On more complex pages tabs (e.g from field_group) are used. Inside each tab is a view.
Tabs can be activated on page load using anchor links.

e.g.
https://site/page -> opens the default tab Tab1
https://site/page#tab_fragment2 -> opens the second tab Tab2

On reloading a filtered view (which resides in a non default tab Tab2) upon clicking on the "next page" of the pager the default tab Tab1 is shown instead of the Tab2 containing the view with the next page.

This prevents a lot of automatic ajax interaction from working correctly.

Steps to reproduce

Proposed resolution

Allow client side #fragments (e.g. anchor links) for views pagination links.
Make an option for the pager called "client side fraqments:" which is added to the pager link.

Remaining tasks

User interface changes

API changes

Data model changes

Release notes snippet