Add preference to hide following/followers lists (#7532)

* Add preference to hide following/followers lists

- Public pages
- ActivityPub collections (does not return pages but does give total)
- REST API (unless it's your own) (does not federate)

Fix #6901

* Add preference

* Add delegation

* Fix issue

* Fix issue

app/views/accounts/_follow_grid.html.haml

@@ -1,5 +1,6 @@
-.accounts-grid
+.accounts-grid{ class: accounts.empty? ? 'empty' : '' }
   - if accounts.empty?
+    = image_tag asset_pack_path('elephant_ui_greeting.svg'), alt: '', role: 'presentational'
     = render partial: 'accounts/nothing_here'
   - else
     = render partial: 'accounts/grid_card', collection: accounts, as: :account, cached: !user_signed_in?

app/views/accounts/_follow_grid_hidden.html.haml

@@ -0,0 +1,3 @@
+.accounts-grid.empty
+  = image_tag asset_pack_path('elephant_ui_greeting.svg'), alt: '', role: 'presentational'
+  %p.nothing-here= t('accounts.network_hidden')