Remove usage of deprecated UrlGeneratorInterface::generateFromPath()

Problem/Motivation

Drupal\Core\Routing\UrlGeneratorInterface::generateFromPath() is marked as deprecated before the 8.0.0 release.

In order to remove it, we must remove usages of it.

Proposed resolution

Remove usages of Drupal\Core\Routing\UrlGeneratorInterface::generateFromPath().

From the generateFromPath() docblock:

   * @deprecated in Drupal 8.0.x-dev and will be removed before Drupal 8.0.0.
   *   To generate URLs for Drupal routes (that is, most pages generated by
   *   Drupal), see UrlGeneratorInterface::generateFromRoute() instead. For
   *   non-routed local URIs relative to the base path (like robots.txt) see
   *   \Drupal\Core\Utility\UnroutedUrlAssembler.

UroutedUrlAssembler is a service:

  unrouted_url_assembler:
    class: Drupal\Core\Utility\UnroutedUrlAssembler
    arguments: ['@request_stack', '@path_processor_manager', '%filter_protocols%']

See child issues for ongoing list of removals.

Remaining tasks

Need to identify each usage here and create sub tasks for each. Check for duplicate issues.

User interface changes

API changes

Original report by @gumanist

Beta phase evaluation