Rework pool versions index/diff views

- Changed to using the diff-body CSS class
-- Removed unneeded CSS style file
- Removed trailing whitespace after the >>> link
-- It was causing artifact line-throughs to appear after the link
- Changed the diff link to only render when a text field has changed
-- Because the post changes are already shown on the index view
- Specifically add <br> to statuses to cause line breaks

app/helpers/pool_versions_helper.rb

@@ -1,26 +0,0 @@
-module PoolVersionsHelper
-  def pool_versions_listing_type
-    params.dig(:search, :pool_id).present? ? :revert : :standard
-  end
-
-  def pool_version_status_diff(pool_version)
-    cur = pool_version
-    prev = pool_version.previous
-
-    return "New" if prev.blank?
-
-    status = []
-    status += ["Renamed"] if cur.name != prev.name
-    status += ["DescChanged"] if cur.description != prev.description
-    status += ["Deleted"] if cur.is_deleted? && !prev.is_deleted?
-    status += ["Undeleted"] if !cur.is_deleted? && prev.is_deleted?
-    status += ["Activated"] if cur.is_active? && !prev.is_active?
-    status += ["Deactivated"] if !cur.is_active? && prev.is_active?
-    status.join(" ")
-  end
-
-  def pool_page_diff(pool_version, other_version)
-    pattern = Regexp.new('(?:<.+?>)|(?:\w+)|(?:[ \t]+)|(?:\r?\n)|(?:.+?)')
-    DiffBuilder.new(pool_version.description, other_version.description, pattern).build
-  end
-end