contextual route name does not exists

Problem/Motivation

Hello, a error is found when using draggable views inside a block. The contextual hook creates a route that does not exist, causing contextual core module to raise an exception.

Steps to reproduce

Create a block.

Proposed resolution

Check if the route exists before trying to add to contextual links in draggableviews_contextual_links_alter.

Remaining tasks

User interface changes

API changes

Data model changes