Remove whitespace modifiers from links.html.twig

The template file links.html.twig has a lot of whitespace modifiers. These dashes here, {%- if heading -%}

They were originally added when the template was converted, but don't seem to serve a purpose and can be removed. They might have been there originally for tests but joelpittet confirmed they aren't needed for that now. See the patch here, https://www.drupal.org/node/2465399#comment-9829099

If they can be removed, remove them from the template in the System module, and the template in Classy. To determine if they can be removed we need to look for any instances where links might be rendered inline. That is a place where whitespace could be an issue.

Also, this template has a wrapping if statement:

{% if links -%}
...
{%- endif %}

The if was a direct copy of functionality from when this was a theme function. We cannot verify why it is still needed. Investigate whether it can be removed, and, if so, remove it.

If this issue is worked on after #2455211: Comment field displayed last regardless of assigned weight gets committed, investigate removing the if from the links template in Bartik, as well.

Update : Made the changes in the core links.html.twig template to fix the white-spaces issue as mentioned by Cottser
https://www.drupal.org/node/2472591#comment-10878510

Beta phase evaluation