Trailing Slash Breaks When Multiple Entity Types are Found via $url->getRouteParameters()

Problem/Motivation

Certain modules, such as facets_pretty_paths, add additional route parameters that subsequently need to be looped through in order to find a match for the node bundles to work.

Steps to reproduce

Install trailing_slash module, install facets_pretty_paths and configure a search widget and some facets then add to a basic page (via block regions). Configure the basic page as enabled in trailing_slash settings. Navigate to the page and observe no trailing slash is added.

Proposed resolution

Instead of `$entity_type = key($params);` which only grabs the current (first) item in the array, we should `$entity_types = array_keys($params);` then loop through them in order to find the entity_type

Remaining tasks

n/a

User interface changes

none

API changes

none

Data model changes

none